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8 pages, 8738 KiB

Open AccessCommunication

Recent Results from LUX and Prospects for Dark Matter Searches with LZ

by Vitaly A. Kudryavtsev for the LUX and LZ Collaborations

Universe 2019, 5(3), 73; https://doi.org/10.3390/universe5030073 - 7 Mar 2019

Cited by 3 | Viewed by 3694

Abstract

Weakly Interacting Massive Particle (WIMP) remains one of the most promising dark matter candidates. Many experiments around the world are searching for WIMPs and the best current sensitivity to WIMP-nucleon spin-independent cross-section is about

10^{- 10}

pb. LUX has been one of [...] Read more.

Weakly Interacting Massive Particle (WIMP) remains one of the most promising dark matter candidates. Many experiments around the world are searching for WIMPs and the best current sensitivity to WIMP-nucleon spin-independent cross-section is about

10^{- 10}

pb. LUX has been one of the world-leading experiments in the search for dark matter WIMPs. Results from the LUX experiment on WIMP searches for different WIMP masses are summarised in this paper. The LUX detector will be replaced by its successor, the LUX-ZEPLIN (LZ) detector. With 50 times larger fiducial mass and an increased background rejection power due to specially-designed veto systems, the LZ experiment (due to take first data in 2020) will achieve a sensitivity to WIMPs exceeding the current best limits by more than an order of magnitude (for spin-independent interactions and for WIMP masses exceeding a few GeV). An overview of the LZ experiment is presented and LZ sensitivity is discussed based on the accurately modelled background and the high-sensitivity material screening campaign. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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11 pages, 6008 KiB

Open AccessArticle

A New Approach to Calorimetry in Space-Based Experiments for High-Energy Cosmic Rays

by Gabriele Bigongiari, Oscar Adriani, Sebastiano Albergo, Giovanni Ambrosi, Lucrezia Auditore, Andrea Basti, Eugenio Berti, Lorenzo Bonechi, Simone Bonechi, Massimo Bongi, Valter Bonvicini, Sergio Bottai, Paolo Brogi, Gigi Cappello, Paolo Walter Cattaneo, Raffaello D’Alessandro, Sebastiano Detti, Matteo Duranti, Mauro Fasoli, Noemi Finetti, Valerio Formato, Maria Ionica, Antonio Italiano, Piergiulio Lenzi, Paolo Maestro, Pier Simone Marrocchesi, Nicola Mori, Giulio Orzan, Miriam Olmi, Lorenzo Pacini, Paolo Papini, Maria Grazia Pellegriti, Andrea Rappoldi, Sergio Bruno Ricciarini, Antonella Sciuto, Gianluigi Silvestre, Oleksandr Starodubtsev, Francesco Stolzi, Jung Eun Suh, Arta Sulaj, Alessio Tiberio, Alessia Tricomi, Antonio Trifirò, Marina Trimarchi, Elena Vannuccini, Anna Vedda, Gianluigi Zampa and Nicola Zampa Show full author list Hide full author list

Universe 2019, 5(3), 72; https://doi.org/10.3390/universe5030072 - 7 Mar 2019

Cited by 3 | Viewed by 3761

Abstract

Precise measurements of the energy spectra and of the composition of cosmic rays in the PeV region could improve our knowledge regarding their origin, acceleration mechanism, propagation, and composition. At the present time, spectral measurements in this region are mainly derived from data [...] Read more.

Precise measurements of the energy spectra and of the composition of cosmic rays in the PeV region could improve our knowledge regarding their origin, acceleration mechanism, propagation, and composition. At the present time, spectral measurements in this region are mainly derived from data collected by ground-based detectors, because of the very low particle rates at these energies. Unfortunately, these results are affected by the high uncertainties typical of indirect measurements, which depend on the complicated modeling of the interaction of the primary particle with the atmosphere. A space experiment dedicated to measurements in this energy region has to achieve a balance between the requirements of lightness and compactness, with that of a large acceptance to cope with the low particle rates. CaloCube is a four-year-old R&D project, approved and financed by the Istituto Nazionale di Fisica Nucleare (INFN) in 2014, aiming to optimize the design of a space-borne calorimeter. The large acceptance needed is obtained by maximizing the number of entrance windows, while thanks to its homogeneity and high segmentation this new detector achieves an excellent energy resolution and an enhanced separation power between hadrons and electrons. In order to optimize detector performances with respect to the total mass of the apparatus, comparative studies on different scintillating materials, different sizes of crystals, and different spacings among them have been performed making use of MonteCarlo simulations. In parallel to simulations studies, several prototypes instrumented with CsI(Tl) (Caesium Iodide, Tallium doped) cubic crystals have been constructed and tested with particle beams. Moreover, the last development of CaloCube, the Tracker-In-Calorimeter (TIC) project, financed by the INFN in 2018, is focused on the feasibility of including several silicon layers at different depths in the calorimeter in order to reconstruct the particle direction. In fact, an important requirement for

γ

-ray astronomy is to have a good angular resolution in order to allow precise identification of astrophysical sources in space. In respect to the traditional approach of using a tracker with passive material in front of the calorimeter, the TIC solution can save a significant amount of mass budget in a space satellite experiment, which can then be exploited to improve the acceptance and the resolution of the calorimeter. In this paper, the status of the project and perspectives for future developments are presented. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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10 pages, 543 KiB

Open AccessArticle

Directed Flow in Microscopic Models in Relativistic A+A Collisions

by Larissa Bravina, Yurii Kvasiuk, Sergey Sivoklokov, Oleksandr Vitiuk and Evgeny Zabrodin

Universe 2019, 5(3), 69; https://doi.org/10.3390/universe5030069 - 5 Mar 2019

Cited by 6 | Viewed by 3118

Abstract

Evolution of directed flow of charged particles produced in relativistic heavy-ion collisions at energies

4 \leq \sqrt{s} \leq 19.6

GeV is considered within two microscopic transport models, ultra-relativistic quantum molecular dynamics (UrQMD) and quark-gluon string model (QGSM). In both models, the directed flow [...] Read more.

Evolution of directed flow of charged particles produced in relativistic heavy-ion collisions at energies

4 \leq \sqrt{s} \leq 19.6

GeV is considered within two microscopic transport models, ultra-relativistic quantum molecular dynamics (UrQMD) and quark-gluon string model (QGSM). In both models, the directed flow of protons changes its sign at midrapidity from antiflow to normal flow with decreasing energy of collisions, whereas the flows of mesons and antiprotons remain antiflow-oriented. For lighter colliding systems, such as Cu+Cu or S+S, changing of the proton directed flow occurs at lower bombarding energies and for more central topologies compared to a heavy Au+Au system. The differences can be explained by dissimilar production zones of different hadrons and by the influence of spectators. Directed flows of most abundant hadronic species at midrapidity are found to be formed within t = 10–12 fm/c after the beginning of nuclear collision. The influence of hard and soft mean-field potentials on the directed flow is also studied. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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9 pages, 2196 KiB

Open AccessCommunication

ANTARES and KM3NeT: The Latest Results of the Neutrino Telescopes in the Mediterranean

by Matteo Sanguineti

Universe 2019, 5(2), 65; https://doi.org/10.3390/universe5020065 - 21 Feb 2019

Cited by 5 | Viewed by 2956

Abstract

The measurement of cosmic neutrinos is a new and unique method to observe the Universe. Neutrinos are chargeless, weakly-interacting particles that can provide information about the interior of an astrophysical object for cosmological distances. Indeed, they are a complementary probe with respect to [...] Read more.

The measurement of cosmic neutrinos is a new and unique method to observe the Universe. Neutrinos are chargeless, weakly-interacting particles that can provide information about the interior of an astrophysical object for cosmological distances. Indeed, they are a complementary probe with respect to other messengers such as multi-wavelength light and charged cosmic rays, allowing the observation of the far Universe and providing information on the production mechanism. Here, the neutrino telescopes in the Mediterranean Sea that are operating or in progress will be reviewed. The ANTARES (Astronomy with a Neutrino Telescope and Abyss environmental RESearch) detector is the largest neutrino telescope currently in operation in the Mediterranean Sea and the first operating in sea water. Some of the ANTARES results will be summarized, including diffuse, point-like, and multi-messenger source searches. Finally, the future km

^{3}

-scale telescope KM3NeT (Cubic Kilometre Neutrino Telescope) will be described focusing on the expected performances and sensitivities. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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8 pages, 258 KiB

Open AccessArticle

Particle Production at High Energy: DGLAP, BFKL and Beyond

by Jamal Jalilian-Marian

Universe 2019, 5(2), 64; https://doi.org/10.3390/universe5020064 - 20 Feb 2019

Cited by 1 | Viewed by 2482

Abstract

Particle production in high energy hadronic/nuclear collisions in the Bjorken limit

Q^{2}, \sqrt{s} \to \infty

can be described in the collinear factorization framework of perturbative Quantum ChromoDynamics (QCD). On the other hand in the Regge limit, at fixed and not too [...] Read more.

Particle production in high energy hadronic/nuclear collisions in the Bjorken limit

Q^{2}, \sqrt{s} \to \infty

can be described in the collinear factorization framework of perturbative Quantum ChromoDynamics (QCD). On the other hand in the Regge limit, at fixed and not too high

Q^{2}

with

\sqrt{s} \to \infty

, a

k_{⊥}

factorization approach (or a generalization of it) is the appropriate framework. A new effective action approach to QCD in the Regge limit, known as the Color Glass Condensate (CGC) formalism, has been developed which allows one to investigate particle production in high energy collisions in the kinematics where collinear factorization breaks down. Here we give a brief overview of particle production in CGC framework and the evolution equation which governs energy dependence of the observables in this formalism. We show that the new evolution equation reduces to previously known evolution equations in the appropriate limits. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

19 pages, 547 KiB

Open AccessArticle

Two Types of Jets and Quark and Chromon Model in QCD

by Yongmin Cho

Universe 2019, 5(2), 62; https://doi.org/10.3390/universe5020062 - 14 Feb 2019

Cited by 3 | Viewed by 3013

Abstract

We discuss the importance of the color reflection symmetry of the Abelian decomposition in QCD. The Abelian decomposition breaks up the color gauge field to three parts, the neuron, chromon, and the topological monopole, gauge independently. Moreover, it refines the Feynman diagram in [...] Read more.

We discuss the importance of the color reflection symmetry of the Abelian decomposition in QCD. The Abelian decomposition breaks up the color gauge field to three parts, the neuron, chromon, and the topological monopole, gauge independently. Moreover, it refines the Feynman diagram in such a way that the conservation of color is explicit. This leads us to generalize the quark model to the quark and chromon model. We show how the Abelian decomposition reduces the non-Abelian color gauge symmetry to the simple discrete 24 element color reflection symmetry which assumes the role of the color gauge symmetry and plays the central role in the quark and chromon model. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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8 pages, 2473 KiB

Open AccessCommunication

Bayesian Analysis for Extracting Properties of the Nuclear Equation of State from Observational Data Including Tidal Deformability from GW170817

by Alexander Ayriyan, David Alvarez-Castillo, David Blaschke and Hovik Grigorian

Universe 2019, 5(2), 61; https://doi.org/10.3390/universe5020061 - 14 Feb 2019

Cited by 23 | Viewed by 3230

Abstract

We develop a Bayesian analysis method for selecting the most probable equation of state under a set of constraints from compact star physics, which now include the tidal deformability from GW170817. We apply this method for the first time to a two-parameter family [...] Read more.

We develop a Bayesian analysis method for selecting the most probable equation of state under a set of constraints from compact star physics, which now include the tidal deformability from GW170817. We apply this method for the first time to a two-parameter family of hybrid equations of state that is based on realistic models for the hadronic phase (KVORcut02) and the quark matter phase (SFM

α

) which produce a third family of hybrid stars in the mass–radius diagram. One parameter (

α

) characterizes the screening of the string tension in the string-flip model of quark matter while the other (

Δ_{P}

) belongs to the mixed phase construction that mimics the thermodynamics of pasta phases and includes the Maxwell construction as a limiting case for

Δ_{P} = 0

. We present the corresponding results for compact star properties like mass, radius and tidal deformabilities and use empirical data for them in the newly developed Bayesian analysis method to obtain the probabilities for the model parameters within their considered range. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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11 pages, 3586 KiB

Open AccessArticle

The Investigation on the Dark Sector at the PADME Experiment

by Fabio Ferrarotto

Universe 2019, 5(2), 59; https://doi.org/10.3390/universe5020059 - 12 Feb 2019

Viewed by 2836

Abstract

In this paper, we present the design and expected performance of the various detectors of the PADME experiment. The experiment design has been optimized for the detection of the final state photons produced along with a “Dark Photon”, decaying to invisible particles, in [...] Read more.

In this paper, we present the design and expected performance of the various detectors of the PADME experiment. The experiment design has been optimized for the detection of the final state photons produced along with a “Dark Photon”, decaying to invisible particles, in the annihilation a of 550 MeV positron with an atomic electron of a thin target. The PADME experiment has been built in a new dedicated experimental hall at the Beam Test Facility (BTF) of the INFN Frascati National Laboratories and has been taking data since the third quarter of 2018. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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18 pages, 1164 KiB

Open AccessArticle

Weak Values and Two-State Vector Formalism in Elementary Scattering and Reflectivity—A New Effect

by C. Aris Chatzidimitriou-Dreismann

Universe 2019, 5(2), 58; https://doi.org/10.3390/universe5020058 - 12 Feb 2019

Cited by 7 | Viewed by 4606

Abstract

The notions of Weak Value (WV) and Two-State Vector Formalism (TSVF), firstly introduced by Aharonov and collaborators, provide a quantum-theoretical formalism of extracting new information from a system in the limit of small disturbances to its state. Here, we explore two applications to [...] Read more.

The notions of Weak Value (WV) and Two-State Vector Formalism (TSVF), firstly introduced by Aharonov and collaborators, provide a quantum-theoretical formalism of extracting new information from a system in the limit of small disturbances to its state. Here, we explore two applications to the case of non-relativistic two-body scattering with one body weakly interacting with its environment. We present a physically compelling analysis of a new quantum effect: momentum transfer deficit and an accompanying enhanced energy transfer; or, equivalently, an apparent mass-deficit of the struck body. First, incoherent inelastic neutron scattering (INS) from protons of H

_{2}

molecules in C-nanotubes is investigated. The data of the H

_{2}

translational motion along the nanotube shows that the neutron apparently exchanges energy and momentum with a fictitious particle with mass of 0.64 atomic mass units (a.m.u.), which is in blatant contradiction with the expected value of 2 a.m.u. Second, the same theory is applied to neutron reflectivity—which is elastic and coherent—from the interface of (single crystal) Si with H

_{2}

O-D

_{2}

O liquid mixtures. The data shows a striking enhanced reflectivity in a wide range of momentum transfers, which is tantamount to a momentum-transfer deficit with respect to conventional expectations. However, these effects find a natural interpretation within the WV-TSVF theoretical analysis under consideration. In summary, both scattering effects contradict conventional theoretical expectations, thus also supporting the novelty of the theoretical framework of WV and TVSF. Additionally, it should be pointed out that the two dynamical variables in the interaction Hamiltonian of the theoretical model belong to two different physical bodies. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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11 pages, 1107 KiB

Open AccessCommunication

Searches for Electric Dipole Moments—Overview of Status and New Experimental Efforts

by Florian Kuchler and on behalf of the TUCAN and HeXeEDM Collaborations

Universe 2019, 5(2), 56; https://doi.org/10.3390/universe5020056 - 9 Feb 2019

Cited by 3 | Viewed by 3673

Abstract

Searches for permanent electric dipole moments (EDMs) of fundamental particles, atoms and molecules are promising experiments to constrain and potentially reveal beyond Standard Model (SM) physics. A non-zero EDM is a direct manifestation of time-reversal (T) violation, and, equivalently, violation of the combined [...] Read more.

Searches for permanent electric dipole moments (EDMs) of fundamental particles, atoms and molecules are promising experiments to constrain and potentially reveal beyond Standard Model (SM) physics. A non-zero EDM is a direct manifestation of time-reversal (T) violation, and, equivalently, violation of the combined operation of charge-conjugation (C) and parity inversion (P). Identifying new sources of CP violation can help to solve fundamental puzzles of the SM, e.g., the observed baryon-asymmetry in the Universe. Theoretical predictions for magnitudes of EDMs in the SM are many orders of magnitude below current experimental limits. However, many theories beyond the SM require larger EDMs. Experimental results, especially when combined in a global analysis, impose strong constraints on CP violating model parameters. Including an overview of EDM searches, I will focus on the future neutron EDM experiment at TRIUMF (Vancouver). For this effort, the TUCAN (TRIUMF Ultra Cold Advanced Neutron source) collaboration is aiming to build a strong, world leading source of ultra cold neutrons (UCN) based on a unique combination of a spallation target and a superfluid helium UCN converter. Another focus will be the search for an EDM of the diamagnetic atom

^{129}

Xe using a

^{3}

He comagnetometer and SQUID detection. The HeXeEDM collaboration has taken EDM data in 2017 and 2018 in the magnetically shielded room (BMSR-2) at PTB Berlin. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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11 pages, 1760 KiB

Open AccessArticle

Highlights from GERDA: Probing the Majorana Neutrino Mass at 100 meV

by Carla Maria Cattadori and on behalf of the GERDA Collaboration

Universe 2019, 5(2), 55; https://doi.org/10.3390/universe5020055 - 7 Feb 2019

Viewed by 3009

Abstract

Since 2010, the Gerda experiment at Laboratori Nazionali del Gran Sasso (LNGS) operates searching for neutrinoless double beta decay (

0 ν β β

) of

^{76}

Ge to the ground and excited states of

^{76}

Se.

0 ν β β

is an [...] Read more.

Since 2010, the Gerda experiment at Laboratori Nazionali del Gran Sasso (LNGS) operates searching for neutrinoless double beta decay (

0 ν β β

) of

^{76}

Ge to the ground and excited states of

^{76}

Se.

0 ν β β

is an ultra-rare process whose detection would directly establish the Majorana nature of the neutrino and provide a direct measurement of its mass. Since the apparatus upgrade in 2013–2015, the collaboration released the third update of the achieved results at the Neutrino 2018 Conference. The hardware upgrade and the fine tuning of the powerful analysis tools to reconstruct the event energy and to discriminate the background allowed the achievement of the energy resolution of 3 keV and 3.6 keV for Broad Energy Germanium (BEGe) and Coaxial Germanium (Coax) detectors, respectively, and an unprecedented low background index of 0.6 · 10

^{- 3}

cts/(keV·kg·yr)

10^{- 3}

cts/(keV·kg·yr) in a 230 keV netto range centered at

Q_{β β}

in the exposure of 58.93 kg·yr. No evidence of the

0 ν β β

decay is found at the

Q_{β β}

= 2039.1 keV, and the limit of 0.9 ·

10^{26}

yr on the half-life (

T_{1 / 2}^{0 ν}

) at 90% C.L. is set. This corresponds to the limit range for the effective Majorana neutrino mass

m_{e e}

of 110–260 meV. The Gerda sensitivity in terms of background index, energy resolution and exposure is the best achieved so far in

^{76}

Ge double beta decay experiments, the energy resolution and background in the Region Of Interest (ROI) allow Gerda to operate in a background-free regime and to set a world record. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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4 pages, 205 KiB

Open AccessCommunication

Mathematical Formulation of the No-Go Theorem in Horndeski Theory

by Sergey Mironov

Universe 2019, 5(2), 52; https://doi.org/10.3390/universe5020052 - 2 Feb 2019

Cited by 11 | Viewed by 2494

Abstract

We present a brief mathematical-like formulation of the no-go theorem, useful for bouncing and wormhole solutions in Horndeski theory. The no-go theorem is almost identical in the cases of flat FLRW geometry and static, spherically symmetric setting, hence, we generalize the argument of [...] Read more.

We present a brief mathematical-like formulation of the no-go theorem, useful for bouncing and wormhole solutions in Horndeski theory. The no-go theorem is almost identical in the cases of flat FLRW geometry and static, spherically symmetric setting, hence, we generalize the argument of the theorem so that it has consise and universal form. We also give a strict mathematical proof of the no-go argument. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

24 pages, 3000 KiB

Open AccessArticle

An Accelerating Universe without Lambda: Delta Gravity Using Monte Carlo

by Jorge Alfaro, Marco San Martín and Joaquín Sureda

Universe 2019, 5(2), 51; https://doi.org/10.3390/universe5020051 - 1 Feb 2019

Cited by 5 | Viewed by 3748

Abstract

A gravitational field model based on two symmetric tensors,

g_{μ ν}

and

{\tilde{g}}_{μ ν}

, is studied, using a Markov Chain Monte Carlo (MCMC) analysis with the most updated catalog of SN-Ia. In this model, new matter fields are added [...] Read more.

A gravitational field model based on two symmetric tensors,

g_{μ ν}

and

{\tilde{g}}_{μ ν}

, is studied, using a Markov Chain Monte Carlo (MCMC) analysis with the most updated catalog of SN-Ia. In this model, new matter fields are added to the original matter fields, motivated by an additional symmetry (

\tilde{δ}

symmetry). We call them

\tilde{δ}

matter fields. This theory predicts an accelerating Universe without the need to introduce a cosmological constant

Λ

by hand in the equations. We obtained a very good fit to the SN-Ia Data, and with this, we found the two free parameters of the theory called C and

L_{2}

. With these values, we have fixed all the degrees of freedom in the model. The last

H_{0}

local value measurement is in tension with the CMB Data from Planck. Based on an absolute magnitude

M_{V} = - 19.23

for the SN, Delta Gravity finds

H_{0}

to be

74.47 \pm 1.63

km/(s Mpc). This value is in concordance with the last measurement of the

H_{0}

local value,

73.83 \pm 1.48

km/(s Mpc). Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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10 pages, 753 KiB

Open AccessArticle

Mass Gap in Nonperturbative Quantization à La Heisenberg

by Vladimir Dzhunushaliev and Vladimir Folomeev

Universe 2019, 5(2), 50; https://doi.org/10.3390/universe5020050 - 31 Jan 2019

Viewed by 2469

Abstract

The approximate method of solving nonperturbative Dyson-Schwinger equations by cutting off this infinite set of equations to three equations is considered. The gauge noninvariant decomposition of SU(3) degrees of freedom into SU(2) × U(1) and SU(3)/(SU(2) × U(1)) degrees of freedom is used. [...] Read more.

The approximate method of solving nonperturbative Dyson-Schwinger equations by cutting off this infinite set of equations to three equations is considered. The gauge noninvariant decomposition of SU(3) degrees of freedom into SU(2) × U(1) and SU(3)/(SU(2) × U(1)) degrees of freedom is used. SU(2) × U(1) degrees of freedom have nonzero quantum average, and SU(3)/(SU(2) × U(1)) have zero quantum average. To close these equations, some approximations are employed. Regular spherically symmetric finite energy solutions of these equations are obtained. Energy spectrum of these solutions is studied. The presence of a mass gap is shown. The obtained solutions describe quasi-particles in a quark-gluon plasma. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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10 pages, 12842 KiB

Open AccessCommunication

The ICARUS Experiment

by Christian Farnese and on behalf of the ICARUS Collaboration

Universe 2019, 5(2), 49; https://doi.org/10.3390/universe5020049 - 29 Jan 2019

Cited by 6 | Viewed by 3318

Abstract

The 760-ton ICARUS T600 detector has completed a successful three-year physics run at the underground LNGS laboratories, searching for atmospheric neutrino interactions and, with the CNGS neutrino beam from CERN, performing a sensitive search for LSND-like anomalous

ν_{e}

appearance, which contributed to [...] Read more.

The 760-ton ICARUS T600 detector has completed a successful three-year physics run at the underground LNGS laboratories, searching for atmospheric neutrino interactions and, with the CNGS neutrino beam from CERN, performing a sensitive search for LSND-like anomalous

ν_{e}

appearance, which contributed to constraining the allowed parameters to a narrow region around

Δ

m

^{2} \sim

eV

^{2}

, where all the experimental results can be coherently accommodated at 90% C.L. The T600 detector underwent a significant overhaul at CERN and has now been moved to Fermilab, to be soon exposed to the Booster Neutrino Beam (BNB) to search for sterile neutrinos within the SBN program, devoted to definitively clarifying the open questions of the presently-observed neutrino anomalies. This paper will address ICARUS’s achievements, its status, and plans for the new run and the ongoing analyses, which will be finalized for the next physics run at Fermilab. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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11 pages, 4510 KiB

Open AccessCommunication

The MoEDAL Experiment at the LHC—A Progress Report

by James Lewis Pinfold

Universe 2019, 5(2), 47; https://doi.org/10.3390/universe5020047 - 29 Jan 2019

Cited by 33 | Viewed by 3638

Abstract

MoEDAL is a pioneering LHC experiment designed to search for anomalously ionizing messengers of new physics. It started data taking at the LHC at a center-of-mass energy of 13 TeV, in 2015. Its ground breaking physics program defines a number of scenarios that [...] Read more.

MoEDAL is a pioneering LHC experiment designed to search for anomalously ionizing messengers of new physics. It started data taking at the LHC at a center-of-mass energy of 13 TeV, in 2015. Its ground breaking physics program defines a number of scenarios that yield potentially revolutionary insights into such foundational questions as: Are there extra dimensions or new symmetries? What is the mechanism for the generation of mass? Does magnetic charge exist? What is the nature of dark matter? After a brief introduction, we report on MoEDAL’s progress to date, including our past, current and expected future physics output. We also discuss two new sub-detectors for MoEDAL: MAPP (Monopole Apparatus for Penetrating Particles) now being prototyped at IP8; and MALL (Monopole Apparatus for very Long Lived particles), currently in the planning stage. I conclude with a brief description of our program for LHC Run-3. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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11 pages, 477 KiB

Open AccessArticle

Symmetry Constrained Decoherence of Conditional Expectation Values

by M. Hamed Mohammady and Alessandro Romito

Universe 2019, 5(2), 46; https://doi.org/10.3390/universe5020046 - 24 Jan 2019

Cited by 1 | Viewed by 2589

Abstract

Conditional expectation values of quantum mechanical observables reflect unique non-classical correlations, and are generally sensitive to decoherence. We consider the circumstances under which such sensitivity to decoherence is removed, namely, when the measurement process is subjected to conservation laws. Specifically, we address systems [...] Read more.

Conditional expectation values of quantum mechanical observables reflect unique non-classical correlations, and are generally sensitive to decoherence. We consider the circumstances under which such sensitivity to decoherence is removed, namely, when the measurement process is subjected to conservation laws. Specifically, we address systems with additive conserved quantities and identify sufficient conditions for the system state such that its coherence plays no role in the conditional expectation values of observables that commute with the conserved quantity. We discuss our findings for a specific model where the system-detector coupling is given by the Jaynes-Cummings interaction, which is relevant to experiments tracking trajectories of qubits in cavities. Our results clarify, among others, the role of coherence in thermal measurements in current architectures for quantum thermodynamics experiments. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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6 pages, 216 KiB

Open AccessCommunication

Quantum Measurements in a Finite Space–Time Domain

by Vladimir Shevchenko

Universe 2019, 5(2), 45; https://doi.org/10.3390/universe5020045 - 24 Jan 2019

Viewed by 2312

Abstract

In this paper, we discuss the quantum Unruh–DeWitt detector, which couples to the field bath for a finite amount of its proper time. It is demonstrated that due to the renormalization procedure, a new dimensionful parameter appears, having the meaning of a detector’s [...] Read more.

In this paper, we discuss the quantum Unruh–DeWitt detector, which couples to the field bath for a finite amount of its proper time. It is demonstrated that due to the renormalization procedure, a new dimensionful parameter appears, having the meaning of a detector’s recovery proper time. It plays no role in the leading order of the perturbation theory, but can be important non-perturbatively. We also analyze the structure of finite time corrections in two cases—perturbative switching on, and switching off when the detector is thermalized. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

10 pages, 6025 KiB

Open AccessCommunication

The Current Status of the Fermilab Muon g–2 Experiment

by Nandita Raha

Universe 2019, 5(2), 43; https://doi.org/10.3390/universe5020043 - 23 Jan 2019

Cited by 1 | Viewed by 3713

Abstract

The anomalous magnetic moment of the muon can be both measured and computed to a very high precision, making it a powerful probe to test the Standard Model and search for new physics. The previous measurement by the Brookhaven E821 experiment found a [...] Read more.

The anomalous magnetic moment of the muon can be both measured and computed to a very high precision, making it a powerful probe to test the Standard Model and search for new physics. The previous measurement by the Brookhaven E821 experiment found a discrepancy from the SM predicted value of about three standard deviations. The Muon g–2 experiment at Fermilab will improve the precision to 140 parts per billion compared to 540 parts per billion of E821 by increasing statistics and using upgraded apparatus. The first run of data taking has been accomplished in Fermilab, where the same level of statistics as E821 has already been attained. This paper, summarizes the current experimental status and briefly describes the data quality of the first run. It compares the statistics of this run with E821 and discusses the future outlook. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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10 pages, 6742 KiB

Open AccessEditor’s ChoiceArticle

QUBIC: Exploring the Primordial Universe with the Q&U Bolometric Interferometer

by Aniello Mennella, Peter Ade, Giorgio Amico, Didier Auguste, Jonathan Aumont, Stefano Banfi, Gustavo Barbaràn, Paola Battaglia, Elia Battistelli, Alessandro Baù, Benoit Bélier, David G. Bennett, Laurent Bergé, Jean Philippe Bernard, Marco Bersanelli, Marie Anne Bigot Sazy, Nathan Bleurvacq, Juan Bonaparte, Julien Bonis, Emory Bunn, David Burke, Daniele Buzi, Alessandro Buzzelli, Francesco Cavaliere, Pierre Chanial, Claude Chapron, Romain Charlassier, Fabio Columbro, Gabriele Coppi, Alessandro Coppolecchia, Rocco D’Agostino, Giuseppe D’Alessandro, Paolo De Bernardis, Giancarlo De Gasperis, Michele De Leo, Marco De Petris, Andres Di Donato, Louis Dumoulin, Alberto Etchegoyen, Adrián Fasciszewski, Cristian Franceschet, Martin Miguel Gamboa Lerena, Beatriz Garcia, Xavier Garrido, Michel Gaspard, Amanda Gault, Donnacha Gayer, Massimo Gervasi, Martin Giard, Yannick Giraud Héraud, Mariano Gómez Berisso, Manuel González, Marcin Gradziel, Laurent Grandsire, Eric Guerard, Jean Christophe Hamilton, Diego Harari, Vic Haynes, Sophie Henrot Versillé, Duc Thuong Hoang, Nicolas Holtzer, Federico Incardona, Eric Jules, Jean Kaplan, Andrei Korotkov, Christian Kristukat, Luca Lamagna, Sotiris Loucatos, Thibaut Louis, Amy Lowitz, Vladimir Lukovic, Raùl Horacio Luterstein, Bruno Maffei, Stefanos Marnieros, Silvia Masi, Angelo Mattei, Andrew May, Mark McCulloch, Maria Clementina Medina, Lorenzo Mele, Simon J. Melhuish, Ludovic Montier, Louise Mousset, Luis Mariano Mundo, John Anthony Murphy, James David Murphy, Creidhe O’Sullivan, Emiliano Olivieri, Alessandro Paiella, Francois Pajot, Andrea Passerini, Hernan Pastoriza, Alessandro Pelosi, Camille Perbost, Maurizio Perciballi, Federico Pezzotta, Francesco Piacentini, Michel Piat, Lucio Piccirillo, Giampaolo Pisano, Gianluca Polenta, Damien Prêle, Roberto Puddu, Damien Rambaud, Pablo Ringegni, Gustavo E. Romero, Maria Salatino, Alessandro Schillaci, Claudia G. Scóccola, Stephen P. Scully, Sebastiano Spinelli, Guillaume Stankowiak, Michail Stolpovskiy, Federico Suarez, Andrea Tartari, Jean Pierre Thermeau, Peter Timbie, Maurizio Tomasi, Steve A. Torchinsky, Matthieu Tristram, Carole E. Tucker, Gregory S. Tucker, Sylvain Vanneste, Daniele Viganò, Nicola Vittorio, Fabrice Voisin, Robert Watson, Francois Wicek, Mario Zannoni and Antonio Zullo Show full author list Hide full author list

Universe 2019, 5(2), 42; https://doi.org/10.3390/universe5020042 - 23 Jan 2019

Cited by 23 | Viewed by 6116

Abstract

In this paper, we describe QUBIC, an experiment that will observe the polarized microwave sky with a novel approach, which combines the sensitivity of state-of-the-art bolometric detectors with the systematic effects control typical of interferometers. QUBIC’s unique features are the so-called “self-calibration”, a [...] Read more.

In this paper, we describe QUBIC, an experiment that will observe the polarized microwave sky with a novel approach, which combines the sensitivity of state-of-the-art bolometric detectors with the systematic effects control typical of interferometers. QUBIC’s unique features are the so-called “self-calibration”, a technique that allows us to clean the measured data from instrumental effects, and its spectral imaging power, i.e., the ability to separate the signal into various sub-bands within each frequency band. QUBIC will observe the sky in two main frequency bands: 150 GHz and 220 GHz. A technological demonstrator is currently under testing and will be deployed in Argentina during 2019, while the final instrument is expected to be installed during 2020. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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14 pages, 442 KiB

Open AccessCommunication

Hamiltonian Approach to QCD at Finite Temperature

by Hugo Reinhardt, Davide Campagnari and Markus Quandt

Universe 2019, 5(2), 40; https://doi.org/10.3390/universe5020040 - 22 Jan 2019

Cited by 1 | Viewed by 2498

Abstract

A novel approach to the Hamiltonian formulation of quantum field theory at finite temperature is presented. The temperature is introduced by compactification of a spatial dimension. The whole finite-temperature theory is encoded in the ground state on the spatial manifold [...] Read more.

A novel approach to the Hamiltonian formulation of quantum field theory at finite temperature is presented. The temperature is introduced by compactification of a spatial dimension. The whole finite-temperature theory is encoded in the ground state on the spatial manifold

S^{1} (L) \times R^{2}

where L is the length of the compactified dimension which defines the inverse temperature. The approach is then applied to the Hamiltonian formulation of QCD in Coulomb gauge to study the chiral phase transition at finite temperatures. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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12 pages, 796 KiB

Open AccessArticle

Passive Advection of a Vector Field by Compressible Turbulent Flow: Renormalizations Group Analysis near d = 4

by Nikolay V. Antonov, Nikolay M. Gulitskiy, Maria M. Kostenko and Tomáš Lučivjanský

Universe 2019, 5(1), 37; https://doi.org/10.3390/universe5010037 - 18 Jan 2019

Cited by 3 | Viewed by 2889

Abstract

The renormalization group approach and the operator product expansion technique are applied to the model of a passively advected vector field by a turbulent velocity field. The latter is governed by the stochastic Navier-Stokes equation for a compressible fluid. The model is considered [...] Read more.

The renormalization group approach and the operator product expansion technique are applied to the model of a passively advected vector field by a turbulent velocity field. The latter is governed by the stochastic Navier-Stokes equation for a compressible fluid. The model is considered in the vicinity of space dimension

d = 4

and the perturbation theory is constructed within a double expansion scheme in y and

ε = 4 - d

, where y describes scaling behaviour of the random force that enters the Navier-Stokes equation. The properties of the correlation functions are investigated, and anomalous scaling and multifractal behaviour are established. All calculations are performed in the leading order of y,

ε

expansion (one-loop approximation). Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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9 pages, 282 KiB

Open AccessArticle

Computing Neutron Capture Rates in Neutron-Degenerate Matter

by Bryn Knight and Liliana Caballero

Universe 2019, 5(1), 36; https://doi.org/10.3390/universe5010036 - 18 Jan 2019

Cited by 2 | Viewed by 3024

Abstract

Neutron captures are likely to occur in the crust of accreting neutron stars (NSs). Their rate depends on the thermodynamic state of neutrons in the crust. At high densities, neutrons are degenerate. We find degeneracy corrections to neutron capture rates off nuclei, using [...] Read more.

Neutron captures are likely to occur in the crust of accreting neutron stars (NSs). Their rate depends on the thermodynamic state of neutrons in the crust. At high densities, neutrons are degenerate. We find degeneracy corrections to neutron capture rates off nuclei, using cross sections evaluated with the reaction code TALYS. We numerically integrate the relevant cross sections over the statistical distribution functions of neutrons at thermodynamic conditions present in the NS crust. We compare our results to analytical calculations of these corrections based on a power-law behavior of the cross section. We find that although an analytical integration can simplify the calculation and incorporation of the results for nucleosynthesis networks, there are uncertainties caused by departures of the cross section from the power-law approach at energies close to the neutron chemical potential. These deviations produce non-negligible corrections that can be important in the NS crust. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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10 pages, 6498 KiB

Open AccessArticle

Muon Radiography of Ancient Mines: The San Silvestro Archaeo-Mining Park (Campiglia Marittima, Tuscany)

by Guglielmo Baccani, Lorenzo Bonechi, Massimo Bongi, Debora Brocchini, Nicola Casagli, Roberto Ciaranfi, Luigi Cimmino, Vitaliano Ciulli, Raffaello D’Alessandro, Chiara Del Ventisette, Andrea Dini, Giovanni Gigli, Sandro Gonzi, Silvia Guideri, Luca Lombardi, Barbara Melon, Nicola Mori, Massimiliano Nocentini, Pasquale Noli, Giulio Saracino and Lorenzo Viliani Show full author list Hide full author list

Universe 2019, 5(1), 34; https://doi.org/10.3390/universe5010034 - 17 Jan 2019

Cited by 26 | Viewed by 4980

Abstract

Muon absorption radiography is an imaging technique based on the measurement of the absorption of cosmic ray muons. This technique has recently been used successfully to investigate the presence of unknown cavities in the Bourbon Gallery in Naples and in the Chephren Pyramid [...] Read more.

Muon absorption radiography is an imaging technique based on the measurement of the absorption of cosmic ray muons. This technique has recently been used successfully to investigate the presence of unknown cavities in the Bourbon Gallery in Naples and in the Chephren Pyramid at Cairo. The MIMA detector (Muon Imaging for Mining and Archaeology) is a prototype muon tracker for muon radiography for application in the fields of archaelogy and mining. It is made of three pairs of X-Y planes each consisting of 21 scintillator bars with a silicon photomultiplier readout. The detector is compact, robust, easily transportable, and has a low power consumption: all of which makes the detector ideal for measurements in confined and isolated environments. With this detector, a measurement from inside the Temperino mine in the San Silvestro archaeo-mining park in Tuscany was performed. The park includes about 25 km of mining tunnels arranged on several levels that have been exploited from the Etruscan time. The measured muon absorption was compared to the simulated one, obtained from the information provided by 3D laser scanner measurements and cartographic maps of the mountain above the mine, in order to obtain information about the average density of the rock. This allowed one to confirm the presence of a partially accessible exploitation opening and provided some hints regarding the presence of a high-density body within the rock. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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11 pages, 4497 KiB

Open AccessArticle

Entanglement and Disordered-Enhanced Topological Phase in the Kitaev Chain

by Liron Levy and Moshe Goldstein

Universe 2019, 5(1), 33; https://doi.org/10.3390/universe5010033 - 17 Jan 2019

Cited by 11 | Viewed by 3353

Abstract

In recent years, tools from quantum information theory have become indispensable in characterizing many-body systems. In this work, we employ measures of entanglement to study the interplay between disorder and the topological phase in 1D systems of the Kitaev type, which can host [...] Read more.

In recent years, tools from quantum information theory have become indispensable in characterizing many-body systems. In this work, we employ measures of entanglement to study the interplay between disorder and the topological phase in 1D systems of the Kitaev type, which can host Majorana end modes at their edges. We find that the entanglement entropy may actually increase as a result of disorder, and identify the origin of this behavior in the appearance of an infinite-disorder critical point. We also employ the entanglement spectrum to accurately determine the phase diagram of the system, and find that disorder may enhance the topological phase, and lead to the appearance of Majorana zero modes in systems whose clean version is trivial. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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8 pages, 1136 KiB

Open AccessCommunication

The ATLAS Fast TracKer—Architecture, Status and High-Level Data Quality Monitoring Framework

by Alexandros Marantis on Behalf of the ATLAS Collaboration

Universe 2019, 5(1), 32; https://doi.org/10.3390/universe5010032 - 16 Jan 2019

Cited by 2 | Viewed by 3137

Abstract

The Fast Tracker (FTK) is a highly parallel processor dedicated to a quick and efficient reconstruction of tracks in the Pixel and Semiconductor Tracker (SCT) detectors of the ATLAS experiment at LHC. It is designed to identify charged particle tracks with transverse momentum [...] Read more.

The Fast Tracker (FTK) is a highly parallel processor dedicated to a quick and efficient reconstruction of tracks in the Pixel and Semiconductor Tracker (SCT) detectors of the ATLAS experiment at LHC. It is designed to identify charged particle tracks with transverse momentum above 1 GeV and reconstruct their parameters at an event rate of up to 100 kHz. The average latency of the processing is below 100 μs at the expected collision intensities. This performance is achieved by using custom ASIC chips with associative memory for pattern matching, while modern FPGAs calculate the track parameters. This paper describes the architecture, the current status and a High-Level Data Quality Monitoring framework of the FTK system. This monitoring framework provides an online comparison of the FTK hardware output with the FTK functional simulation, which is run on the pixel and SCT detector data at a low rate, allowing the detection of non-expected outputs of the FTK system. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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12 pages, 4612 KiB

Open AccessCommunication

Highlights from the Compact Muon Solenoid (CMS) Experiment

by Saranya Samik Ghosh and on behalf of the CMS Collaboration

Universe 2019, 5(1), 28; https://doi.org/10.3390/universe5010028 - 16 Jan 2019

Cited by 2 | Viewed by 3621

Abstract

The highlights of the recent activities and physics results leading up to the summer of 2018 from the Compact Muon Solenoid (CMS) experiment at the CERN Large Hadron Collider (LHC) are presented here. The CMS experiment has a very wide-ranging physics program, and [...] Read more.

The highlights of the recent activities and physics results leading up to the summer of 2018 from the Compact Muon Solenoid (CMS) experiment at the CERN Large Hadron Collider (LHC) are presented here. The CMS experiment has a very wide-ranging physics program, and only a very limited subset of the physics analyses being performed at CMS are discussed here, consisting of several important results from the analysis of proton-proton collision data at center-of-mass energy of 13 TeV. These include important analyses of Higgs boson physics, with the highlight being the first observation of the

t \bar{t} H

production of the Higgs boson, along with analyses pertaining to precision standard model measurements, top quark physics, with the single top production cross-section measurement, and flavor physics, with the important observation of

χ_{b}

(3P) states. Additionally, important searches for physics beyond the standard model are also presented. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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9 pages, 316 KiB

Open AccessCommunication

Experimental Limiting Factors for the Search of μ → eγ at Future Facilities

by Francesco Renga, Gianluca Cavoto, Angela Papa, Emanuele Ripiccini and Cecilia Voena

Universe 2019, 5(1), 27; https://doi.org/10.3390/universe5010027 - 15 Jan 2019

Viewed by 2491

Abstract

The search for the Lepton Flavor Violating decay

μ \to e γ

exploits the most intense continuous muon beams, which can currently deliver ∼

10^{8}

muons per second. In the next decade, accelerator upgrades are expected in various facilities, making it feasible [...] Read more.

The search for the Lepton Flavor Violating decay

μ \to e γ

exploits the most intense continuous muon beams, which can currently deliver ∼

10^{8}

muons per second. In the next decade, accelerator upgrades are expected in various facilities, making it feasible to have continuous beams with an intensity of

10^{9}

or even

10^{10}

muons per second. We investigate the experimental limiting factors that will define the ultimate performances, and hence the sensitivity, in the search for

μ \to e γ

with a continuous beam at these extremely high rates. We then consider some conceptual detector designs and evaluate the corresponding sensitivity as a function of the beam intensity. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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10 pages, 340 KiB

Open AccessArticle

On Quantum Fields at High Temperature

by Ingolf Bischer, Thierry Grandou and Ralf Hofmann

Universe 2019, 5(1), 26; https://doi.org/10.3390/universe5010026 - 15 Jan 2019

Cited by 1 | Viewed by 3136

Abstract

Revisiting the fast fermion damping rate calculation in a thermalized momentum scale eT (QED) and/or momentum scale gT (QCD) plasma at 4-loop order, focus is put on a peculiar perturbative structure which has no equivalent at zero-temperature. Not surprisingly, and in agreement with [...] Read more.

Revisiting the fast fermion damping rate calculation in a thermalized momentum scale eT (QED) and/or momentum scale gT (QCD) plasma at 4-loop order, focus is put on a peculiar perturbative structure which has no equivalent at zero-temperature. Not surprisingly, and in agreement with previous

C^{★}

-algebraic analyses, this structure renders the use of thermal perturbation theory quite questionable. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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18 pages, 4779 KiB

Open AccessArticle

Upgrade of the NA61/SHINE Facility beyond 2020 for an Expanded Physics Programme

by Dag Larsen and on behalf of the NA61/SHINE collaboration

Universe 2019, 5(1), 24; https://doi.org/10.3390/universe5010024 - 10 Jan 2019

Cited by 1 | Viewed by 3519

Abstract

The NA61/SHINE experiment studies hadron production in hadron-hadron, hadron-nucleus and nucleus-nucleus collisions. The physics programme includes the study of the onset of deconfinement and search for the critical point as well as reference measurements for neutrino and cosmic ray experiments. For strong interactions, [...] Read more.

The NA61/SHINE experiment studies hadron production in hadron-hadron, hadron-nucleus and nucleus-nucleus collisions. The physics programme includes the study of the onset of deconfinement and search for the critical point as well as reference measurements for neutrino and cosmic ray experiments. For strong interactions, future plans are to extend the programme of study of the onset of deconfinement by measurements of open-charm and possibly other short-lived, exotic particle production in nucleus-nucleus collisions. This new programme is planned to start after 2020 and requires upgrades to the present NA61/SHINE detector setup. Besides the construction of a large acceptance silicon detector, a 10-fold increase of the event recording rate is foreseen, which will necessitate a general upgrade of most detectors. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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9 pages, 45466 KiB

Open AccessArticle

μCosmics: A Low-Cost Educational Cosmic Ray Telescope

by Apostolos G. Tsirigotis and Antonios Leisos

Universe 2019, 5(1), 23; https://doi.org/10.3390/universe5010023 - 10 Jan 2019

Cited by 11 | Viewed by 3546

Abstract

The design and construction of a small-area, low-cost educational cosmic ray telescope is presented. It can be operated in high-school classrooms or university laboratories. The telescope consists of three small-area scintillation detectors with all the necessary electronics for powering, control, monitoring, and data [...] Read more.

The design and construction of a small-area, low-cost educational cosmic ray telescope is presented. It can be operated in high-school classrooms or university laboratories. The telescope consists of three small-area scintillation detectors with all the necessary electronics for powering, control, monitoring, and data acquisition. The calibration procedures and the performance of the telescope in reconstructing Extensive Air Showers are also presented. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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8 pages, 1363 KiB

Open AccessCommunication

Latest Results from the T2K Neutrino Experiment

by Dean Karlen and on behalf of the T2K Collaboration

Universe 2019, 5(1), 21; https://doi.org/10.3390/universe5010021 - 9 Jan 2019

Cited by 1 | Viewed by 3516

Abstract

The T2K long baseline neutrino oscillation experiment measures muon neutrino disappearance and electron neutrino appearance in accelerator-produced neutrino and anti-neutrino beams. This presentation reports on the analysis of our data from an exposure of

2.6 \times 10^{21}

protons on target. Results for [...] Read more.

The T2K long baseline neutrino oscillation experiment measures muon neutrino disappearance and electron neutrino appearance in accelerator-produced neutrino and anti-neutrino beams. This presentation reports on the analysis of our data from an exposure of

2.6 \times 10^{21}

protons on target. Results for oscillation parameters, including the CP violation parameter and neutrino mass ordering, are shown. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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12 pages, 2369 KiB

Open AccessCommunication

Highlight Talk from Super-Kamiokande

by Yuuki Nakano and On behalf of the Super-Kamiokande Collaboration

Universe 2019, 5(1), 20; https://doi.org/10.3390/universe5010020 - 9 Jan 2019

Viewed by 3561

Abstract

Super-Kamiokande (SK), a 50 kton water Cherenkov detector in Japan, is observing both atmospheric and solar neutrinos. It is also searching for supernova (relic) neutrinos, proton decays and dark matter-like particles. A three-flavor oscillation analysis was conducted with the atmospheric neutrino data to [...] Read more.

Super-Kamiokande (SK), a 50 kton water Cherenkov detector in Japan, is observing both atmospheric and solar neutrinos. It is also searching for supernova (relic) neutrinos, proton decays and dark matter-like particles. A three-flavor oscillation analysis was conducted with the atmospheric neutrino data to study the mass hierarchy, the leptonic CP violation term, and other oscillation parameters. In addition, the observation of solar neutrinos gives precise measurements of the energy spectrum and oscillation parameters. In this proceedings, we given an overview of the latest results from SK and the prospect toward the future project of SK-Gd. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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9 pages, 4871 KiB

Open AccessCommunication

Single-Top Quark Production at CMS

by Priyanka, Kirti Ranjan and Ashutosh Bhardwaj

Universe 2019, 5(1), 19; https://doi.org/10.3390/universe5010019 - 9 Jan 2019

Cited by 1 | Viewed by 3137

Abstract

An overview of recent results of single-top quark production at the LHC using data collected with the CMS detector is presented. The CMS experiment has measured the electroweak production of the top quark in three production modes, namely t-channel, tW-channel, and s-channel. Measurements [...] Read more.

An overview of recent results of single-top quark production at the LHC using data collected with the CMS detector is presented. The CMS experiment has measured the electroweak production of the top quark in three production modes, namely t-channel, tW-channel, and s-channel. Measurements of the rare processes involving a single-top quark with a Z boson and a single-top quark with a

γ

are also discussed. All measurements are in agreement with the standard model prediction, and no sign of physics beyond the standard model is observed. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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9 pages, 1203 KiB

Open AccessCommunication

Overview of the CMS Detector Performance at LHC Run 2

by Martina Ressegotti and On behalf of the CMS Collaboration

Universe 2019, 5(1), 18; https://doi.org/10.3390/universe5010018 - 9 Jan 2019

Cited by 1 | Viewed by 4276

Abstract

The Compact Muon Solenoid (CMS) detector is one of the two multipurpose experiments at the Large Hadron Collider (LHC). It has successfully collected data during Run 1 (2010–2013) and achieved important physics results, like the discovery of the Higgs boson announced in 2012. [...] Read more.

The Compact Muon Solenoid (CMS) detector is one of the two multipurpose experiments at the Large Hadron Collider (LHC). It has successfully collected data during Run 1 (2010–2013) and achieved important physics results, like the discovery of the Higgs boson announced in 2012. Willing to unravel further open questions not yet explained by the standard model, intense activities have been performed to further improve the detector and the trigger before the LHC restart in 2016 (Run 2), in parallel with the upgrade of the LHC. The achieved global performance of the CMS experiment and of several subdetectors will be presented. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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8 pages, 12155 KiB

Open AccessCommunication

Atmospheric Neutrino Search in the ICARUS T600 Detector

by Christian Farnese

Universe 2019, 5(1), 17; https://doi.org/10.3390/universe5010017 - 9 Jan 2019

Cited by 4 | Viewed by 2555

Abstract

The 760-ton liquid argon ICARUS T600 detector performed a successful three-year physics run at the underground LNGS laboratories, studying in particular neutrino oscillations with the CNGS neutrino beam from CERN. This detector has been moved in 2017 to Fermilab after a significant overhauling [...] Read more.

The 760-ton liquid argon ICARUS T600 detector performed a successful three-year physics run at the underground LNGS laboratories, studying in particular neutrino oscillations with the CNGS neutrino beam from CERN. This detector has been moved in 2017 to Fermilab after a significant overhauling and will be exposed soon to the Booster Neutrino Beam acting as the far station to search for sterile neutrinos within the SBN program. The contribution addresses the developed methods and the results of an analysis to identify and reconstruct atmospheric neutrino interactions collected by ICARUS T600 in the underground run at LNGS. Despite the limited statistics, this search demonstrates the excellent quality of the detector reconstruction and the feasibility of an automatic search for the electron neutrino CC interactions in the sub-GeV range, as required for the study of the BNB neutrinos at FNAL. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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12 pages, 430 KiB

Open AccessArticle

Strongly Intensive Observables in the Model with String Fusion

by Vladimir Vechernin and Evgeny Andronov

Universe 2019, 5(1), 15; https://doi.org/10.3390/universe5010015 - 4 Jan 2019

Cited by 8 | Viewed by 2737

Abstract

We calculate the strongly intensive observables for multiplicities in two rapidity windows in the model with independent identical strings taking into account the charge sign of particles. We express the observables through the string pair correlation functions describing the correlations between the same [...] Read more.

We calculate the strongly intensive observables for multiplicities in two rapidity windows in the model with independent identical strings taking into account the charge sign of particles. We express the observables through the string pair correlation functions describing the correlations between the same and opposite sign particles produced in a string decay. We extract these charge-wise string two-particle correlation functions from the ALICE data on the forward-backward correlations and the balance function. Using them we predict the behavior of the charge-wise strongly intensive observables in the model with independent identical strings. We also show that the observable between multiplicities in two acceptance windows separated in rapidity, which is a strongly intensive in the case with independent identical strings, loses this property, when we take into account string fusion effects and a formation of strings of a few different types takes place in a collision. We predict the changes in the behaviour of this observable with energy and collision centrality, arising due to the string fusion phenomena. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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12 pages, 3095 KiB

Open AccessArticle

Open Charm Measurements at CERN SPS Energies with the New Vertex Detector of the NA61/SHINE Experiment: Status and Plans

by Anastasia Merzlaya and On behalf of the NA61/SHINE Collaboration

Universe 2019, 5(1), 14; https://doi.org/10.3390/universe5010014 - 4 Jan 2019

Cited by 3 | Viewed by 2868

Abstract

The study of open charm meson production provides an efficient tool for detailed investigations of the properties of hot and dense matter formed in nucleus-nucleus collisions. The interpretation of the existing data from the CERN Super Proton Synchrotron (SPS) suffers from a lack [...] Read more.

The study of open charm meson production provides an efficient tool for detailed investigations of the properties of hot and dense matter formed in nucleus-nucleus collisions. The interpretation of the existing data from the CERN Super Proton Synchrotron (SPS) suffers from a lack of knowledge about the total charm production rate. To overcome this limitation, the heavy-ion program of the NA61/SHINE experiment at the CERN SPS has been upgraded to allow for precise measurements of particles with a short lifetime. A new vertex detector (Small Acceptance version of the Vertex Detector (SAVD)) was constructed to meet the challenges of open charm measurements in nucleus-nucleus collisions. The first exploratory data taking of Pb + Pb collisions at 150A GeV/c with the SAVD was performed in 2016, and a

D^{0}

signal was extracted in its

D^{0} \to π^{+} + K^{-}

decay channel. This was the first, direct observation of open charm in nucleus-nucleus collisions at the SPS energies. Furthermore, the future plans of open charm measurements in the NA61/SHINE experiment related to the upgraded version of the Vertex Detector are discussed. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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12 pages, 3407 KiB

Open AccessArticle

Physical Justifications and Possible Astrophysical Manifestations of the Projective Theory of Relativity

by Jacques L. Rubin

Universe 2019, 5(1), 13; https://doi.org/10.3390/universe5010013 - 4 Jan 2019

Viewed by 3012

Abstract

The ‘projective theory of relativity’ is a theory developed historically by Oswald Veblen and Banesh Hoffmann, Jan Arnoldus Schouten and David van Dantzig. This theory differs radically from Kaluza-Klein/conformal type theories of spacetime, although it shares with these theories geometric aspects in five-dimensional [...] Read more.

The ‘projective theory of relativity’ is a theory developed historically by Oswald Veblen and Banesh Hoffmann, Jan Arnoldus Schouten and David van Dantzig. This theory differs radically from Kaluza-Klein/conformal type theories of spacetime, although it shares with these theories geometric aspects in five-dimensional spaces. The peculiarity of the projective geometries involved in this theory was that it is based on spaces coordinated by five so-called ‘homogeneous coordinates.’ Since then, no physical observables could be ascribed to these five homogeneous coordinates and, in particular, during the elaboration of this theory which consequently fell completely into oblivion. We will present how this projective theory of relativity can be fully justified physically from the causal structures and localizing protocols involved in so-called ‘relativistic localizing systems’ that extend ‘relativistic positioning systems.’ We explain the correspondence between ‘homogeneous coordinates’ of the projective theory of relativity and the physical observables defined in relativistic localizing systems. Then, possible astrophysical manifestations will be presented based on projective effects, invariance of interactions, or observations with respect to projective transformations. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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9 pages, 623 KiB

Open AccessArticle

The Gravothermal Instability at All Scales: From Turnaround Radius to Supernovae

by Zacharias Roupas

Universe 2019, 5(1), 12; https://doi.org/10.3390/universe5010012 - 3 Jan 2019

Cited by 10 | Viewed by 3037

Abstract

The gravitational instability, responsible for the formation of the structure of the Universe, occurs below energy thresholds and above spatial scales of a self-gravitating expanding region, when thermal energy can no longer counterbalance self-gravity. I argue that at sufficiently-large scales, dark energy may [...] Read more.

The gravitational instability, responsible for the formation of the structure of the Universe, occurs below energy thresholds and above spatial scales of a self-gravitating expanding region, when thermal energy can no longer counterbalance self-gravity. I argue that at sufficiently-large scales, dark energy may restore thermal stability. This stability re-entrance of an isothermal sphere defines a turnaround radius, which dictates the maximum allowed size of any structure generated by gravitational instability. On the opposite limit of high energies and small scales, I will show that an ideal, quantum or classical, self-gravitating gas is subject to a high-energy relativistic gravothermal instability. It occurs at sufficiently-high energy and small radii, when thermal energy cannot support its own gravitational attraction. Applications of the phenomenon include neutron stars and core-collapse supernovae. I also extend the original Oppenheimer–Volkov calculation of the maximum mass limit of ideal neutron cores to the non-zero temperature regime, relevant to the whole cooling stage from a hot proto-neutron star down to the final cold state. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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6 pages, 1300 KiB

Open AccessCommunication

The LUCID Detector for LHC Run-2

by Carla Sbarra and On behalf of the ATLAS Collaboration

Universe 2019, 5(1), 11; https://doi.org/10.3390/universe5010011 - 3 Jan 2019

Cited by 1 | Viewed by 2520

Abstract

LUCID (LUminosity Cerenkov Integrating Detector) is the main luminosity monitor of the ATLAS (A Toroidal LHC Apparatus) experiment at the Large Hadron Collider (LHC) and in particular is the only one capable of providing bunch-by-bunch luminosity information, both online and offline, for all [...] Read more.

LUCID (LUminosity Cerenkov Integrating Detector) is the main luminosity monitor of the ATLAS (A Toroidal LHC Apparatus) experiment at the Large Hadron Collider (LHC) and in particular is the only one capable of providing bunch-by-bunch luminosity information, both online and offline, for all beam conditions and luminosity ranges. LUCID-2 refers to the detector upgrade designed to cope with the running conditions to be met in Run-2 (2015–2018): a center of mass energy of 13 TeV, with 50 pp interactions per bunch-crossing on average and a 25 ns bunch-spacing. This report summarizes all changes with respect to the detector deployed in Run-1 (2010–2012), including smaller sensors for higher granularity, new readout electronics for early signal digitization, and a completely new calibration concept guaranteeing long-term stability of the detector response. In addition, the overall detector performance in Run-2 and preliminary results on luminosity measurements are presented. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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7 pages, 386 KiB

Open AccessCommunication

Four Loop Scalar ϕ⁴ Theory Using the Functional Renormalization Group

by Margaret E. Carrington and Christopher D. Phillips

Universe 2019, 5(1), 9; https://doi.org/10.3390/universe5010009 - 2 Jan 2019

Cited by 2 | Viewed by 2645

Abstract

We work with a symmetric scalar theory with quartic coupling in 4-dimensions. Using a 2PI effective theory and working at 4 loop order, we renormalize with a renormalization group method. All divergences are absorbed by one bare coupling constant and one bare mass [...] Read more.

We work with a symmetric scalar theory with quartic coupling in 4-dimensions. Using a 2PI effective theory and working at 4 loop order, we renormalize with a renormalization group method. All divergences are absorbed by one bare coupling constant and one bare mass which are introduced at the level of the Lagrangian. The method is much simpler than counterterm renormalization, and can be generalized to higher order nPI effective theories. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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10 pages, 693 KiB

Open AccessArticle

Results from the Cuore Experiment ^†

by Alessio Caminata, Douglas Adams, Chris Alduino, Krystal Alfonso, Frank Avignone III, Oscar Azzolini, Giacomo Bari, Fabio Bellini, Giovanni Benato, Andrea Bersani, Matteo Biassoni, Antonio Branca, Chiara Brofferio, Carlo Bucci, Alice Campani, Lucia Canonica, Xi-Guang Cao, Silvia Capelli, Luigi Cappelli, Laura Cardani, Paolo Carniti, Nicola Casali, Davide Chiesa, Nicholas Chott, Massimiliano Clemenza, Simone Copello, Carlo Cosmelli, Oliviero Cremonesi, Richard Creswick, Jeremy Cushman, Antonio D’Addabbo, Damiano D’Aguanno, Ioan Dafinei, Christopher Davis, Stefano Dell’Oro, Milena Deninno, Sergio Di Domizio, Valentina Dompè, Alexey Drobizhev, De-Qing Fang, Guido Fantini, Marco Faverzani, Elena Ferri, Fernando Ferroni, Ettore Fiorini, Massimo Alberto Franceschi, Stuart Freedman, Brian Fujikawa, Andrea Giachero, Luca Gironi, Andrea Giuliani, Paolo Gorla, Claudio Gotti, Thomas Gutierrez, Ke Han, Karsten Heeger, Raul Hennings-Yeomans, Roger Huang, Huan Zhong Huang, Joe Johnston, Giorgio Keppel, Yury Kolomensky, Alexander Leder, Carlo Ligi, Yu-Gang Ma, Laura Marini, Maria Martinez, Reina Maruyama, Yuan Mei, Niccolo Moggi, Silvio Morganti, Tommaso Napolitano, Massimiliano Nastasi, Claudia Nones, Eric Norman, Valentina Novati, Angelo Nucciotti, Irene Nutini, Thomas O’Donnell, Jonathan Ouellet, Carmine Pagliarone, Marco Pallavicini, Luca Pattavina, Maura Pavan, Gianluigi Pessina, Valerio Pettinacci, Cristian Pira, Stefano Pirro, Stefano Pozzi, Ezio Previtali, Andrei Puiu, Carl Rosenfeld, Claudia Rusconi, Michinari Sakai, Samuele Sangiorgio, Benjamin Schmidt, Nick Scielzo, Vivek Singh, Monica Sisti, Danielle Speller, Luca Taffarello, Francesco Terranova, Claudia Tomei, Marco Vignati, Sachinthya Wagaarachchi, Barbara Wang, Bradford Welliver, Jeffrey Wilson, Kevin Wilson, Lindley Winslow, Tom Wise, Luigi Zanotti, Sergio Zimmermann and Stefano Zucchelli Show full author list Hide full author list

Universe 2019, 5(1), 10; https://doi.org/10.3390/universe5010010 - 2 Jan 2019

Cited by 7 | Viewed by 5203

Abstract

The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double beta decay that has been able to reach the 1-ton scale. The detector consists of an array of 988

{TeO}_{2}

crystals arranged in a cylindrical [...] Read more.

The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double beta decay that has been able to reach the 1-ton scale. The detector consists of an array of 988

{TeO}_{2}

crystals arranged in a cylindrical compact structure of 19 towers, each of them made of 52 crystals. The construction of the experiment was completed in August 2016 and the data taking started in spring 2017 after a period of commissioning and tests. In this work we present the neutrinoless double beta decay results of CUORE from examining a total

{TeO}_{2}

exposure of

86.3 kg yr

, characterized by an effective energy resolution of 7.7 keV FWHM and a background in the region of interest of

0.014

counts / (keV kg yr)

. In this physics run, CUORE placed a lower limit on the decay half-life of neutrinoless double beta decay of

^{130} Te > 1.3 \cdot 10^{25}

yr (90% C.L.). Moreover, an analysis of the background of the experiment is presented as well as the measurement of the

^{130}

Te 2

ν β β

decay with a resulting half-life of

T_{1 / 2}^{2 ν} = [7.9 \pm 0.1 (stat .) \pm 0.2 (syst .)] \times 10^{20}

yr which is the most precise measurement of the half-life and compatible with previous results. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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17 pages, 403 KiB

Open AccessEditor’s ChoiceArticle

Finite-Energy Dressed String-Inspired Dirac-Like Monopoles

by Nikolaos E. Mavromatos and Sarben Sarkar

Universe 2019, 5(1), 8; https://doi.org/10.3390/universe5010008 - 30 Dec 2018

Cited by 14 | Viewed by 2921

Abstract

On extending the Standard Model (SM) Lagrangian, through a non-linear Born–Infeld (BI) hypercharge term with a parameter

β

(of dimensions of [mass]

^{2}

), a finite energy monopole solution was claimed by Arunasalam and Kobakhidze. We report on a new class of solutions [...] Read more.

On extending the Standard Model (SM) Lagrangian, through a non-linear Born–Infeld (BI) hypercharge term with a parameter

β

(of dimensions of [mass]

^{2}

), a finite energy monopole solution was claimed by Arunasalam and Kobakhidze. We report on a new class of solutions within this framework that was missed in the earlier analysis. This new class was discovered on performing consistent analytic asymptotic analyses of the nonlinear differential equations describing the model; the shooting method used in numerical solutions to boundary value problems for ordinary differential equations is replaced in our approach by a method that uses diagonal Padé approximants. Our work uses the ansatz proposed by Cho and Maison to generate a static and spherically-symmetric monopole with finite energy and differs from that used in the solution of Arunasalam and Kobakhidze. Estimates of the total energy of the monopole are given, and detection prospects at colliders are briefly discussed. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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10 pages, 992 KiB

Open AccessCommunication

Search for Neutrinos in Super-Kamiokande Associated with Gravitational Wave Events

by Yuuki Nakano and On behalf of the Super-Kamiokande Collaboration

Universe 2019, 5(1), 7; https://doi.org/10.3390/universe5010007 - 29 Dec 2018

Viewed by 3001

Abstract

We report the results from a search in Super-Kamiokande for neutrino signals coincident with gravitational-wave events using a neutrino energy range from

3.5

MeV–100 PeV. We searched for coincident neutrino events within a time window of

\pm 500

s around the gravitational-wave detection [...] Read more.

We report the results from a search in Super-Kamiokande for neutrino signals coincident with gravitational-wave events using a neutrino energy range from

3.5

MeV–100 PeV. We searched for coincident neutrino events within a time window of

\pm 500

s around the gravitational-wave detection time. In this work, we report the number of events within the search-window and the

90 %

confidence level upper limits on the neutrino fluence for each gravitational-wave event. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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9 pages, 17072 KiB

Open AccessArticle

Hellenic Lyceum Cosmic Observatories Network: Status Report and Outreach Activities

by Antonios Leisos, Apostolos Tsirigotis, George Bourlis, Michael Petropoulos, Leonidas Xiros, Ioannis Manthos and Spyros Tzamarias

Universe 2019, 5(1), 4; https://doi.org/10.3390/universe5010004 - 22 Dec 2018

Cited by 8 | Viewed by 2788

Abstract

The HELYCON project aims at the installation of cosmic air-shower detectors on the roofs of high-school buildings in western Greece. During the last four years, the HELYCON project made a substantial progress. Three HELYCON stations were installed and are still in operation at [...] Read more.

The HELYCON project aims at the installation of cosmic air-shower detectors on the roofs of high-school buildings in western Greece. During the last four years, the HELYCON project made a substantial progress. Three HELYCON stations were installed and are still in operation at the Hellenic Open University (HOU) campus, while a small-scale air-shower detector (

μ

Cosmics detector), suitable for in classroom operation, was developed. During the construction and operation of these detectors, many experimental tests and calibration procedures were established, offering the framework for the educational activities of the HELYCON project. In this work, we present the recent developments of the HELYCON project and describe the main aspects of the methodology we use in a five-day training program that introduces the Greek education community to the experimental procedures of HELYCON. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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10 pages, 1884 KiB

Open AccessArticle

Hybrid Detection of High Energy Showers in Urban Environments

by Antonios Leisos, Stavros Nonis, Apostolos Tsirigotis, George Bourlis, Kostas Papageorgiou, Ioannis Gkialas, Ioannis Manthos and Spyros Tzamarias

Universe 2019, 5(1), 3; https://doi.org/10.3390/universe5010003 - 22 Dec 2018

Cited by 10 | Viewed by 2799

Abstract

The Astroneu array comprises 9 large charged particle detectors and 3 RF antennas arranged in three autonomous stations operating at the University Campus of the Hellenic Open University in the city of Patras. Each station of the array detects extensive air showers with [...] Read more.

The Astroneu array comprises 9 large charged particle detectors and 3 RF antennas arranged in three autonomous stations operating at the University Campus of the Hellenic Open University in the city of Patras. Each station of the array detects extensive air showers with primary energy threshold of about 10 TeV, while double station coincidence events select showers with energies higher than

10^{3}

TeV. In such an environment, the radio detection of air showers is challenging. The RF signals besides being extremely weak they also suffer from strong human made electromagnetic noise. In this work, we present the analysis of double station coincidence events and we study the correlation of the RF data with the particle detectors data. We use the experimental information from the particle detectors and the antennas to select very high energy showers and we compare the timing of the RF signals with the timing of the particle detector signals as well as the strength of the RF signals with the simulation predictions. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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7 pages, 4306 KiB

Open AccessCommunication

Result on the Neutrinoless Double Beta Decay Search of ⁸²Se with the CUPID-0 Experiment

by Fabio Bellini, Oscar Azzolini, Maria Teresa Barrera, Jeffrey Beeman, Mattia Beretta, Matteo Biassoni, Chiara Brofferio, Carlo Bucci, Lucia Canonica, Silvia Capelli, Laura Cardani, Paolo Carniti, Nicola Casali, Lorenzo Cassina, Massimiliano Clemenza, Oliverio Cremonesi, Angelo Cruciani, Antonio D’Addabbo, Ioan Dafinei, Sergio Di Domizio, Fernando Ferroni, Luca Gironi, Andrea Giuliani, Paolo Gorla, Claudio Gotti, Giorgio Keppel, Maria Martinez, Silvio Morganti, Sergei Nagorny, Massimiliano Nastasi, Stefano Nisi, Claudia Nones, Donato Orlandi, Lorenzo Pagnanini, Marco Pallavicini, Vincenzo Palmieri, Luca Pattavina, Maura Pavan, Gianluigi Pessina, Valerio Pettinacci, Stefano Pirro, Stefano Pozzi, Ezio Previtali, Andrei Puiu, Claudia Rusconi, Karoline Schäffner, Claudia Tomei, Marco Vignati and Anastasia Zolotarova Show full author list Hide full author list

Universe 2019, 5(1), 2; https://doi.org/10.3390/universe5010002 - 22 Dec 2018

Cited by 1 | Viewed by 3284

Abstract

CUPID-0 is the first large array of scintillating Zn

^{82}

Se cryogenic calorimeters (bolometers) implementing particle identification for the search of the neutrinoless double beta decay (0

ν β β

). The detector consists of 24 enriched Zn

^{82}

Se bolometers for a [...] Read more.

CUPID-0 is the first large array of scintillating Zn

^{82}

Se cryogenic calorimeters (bolometers) implementing particle identification for the search of the neutrinoless double beta decay (0

ν β β

). The detector consists of 24 enriched Zn

^{82}

Se bolometers for a total

^{82}

Se mass of 5.28 kg and it has been taking data in the underground LNGS (Italy) since March 2017. In this article we show how the dual read-out provides a powerful tool for the

α

particles rejection. The simultaneous use of the heat and light information allows us to reduce the background down to (3.2

_{- 1.1}^{+ 1.3}

)×10

^{- 3}

counts/(keV kg year), an unprecedented level for cryogenic calorimeters. In a total exposure of 5.46 kg year Zn

^{82}

Se we set the most stringent limit on the 0

ν β β

decay

^{82}

Se half-life

T_{1 / 2}^{0 ν} > 4.0 \times 10^{24}

year at 90% C.I. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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14 pages, 682 KiB

Open AccessCommunication

Recent Developments and Results on Double Beta Decays with Crystal Scintillators and HPGe Spectrometry

by Alessandro Di Marco, Alexander S. Barabash, Pierluigi Belli, Rita Bernabei, Roman S. Boiko, Viktor B. Brudanin, Fabio Cappella, Vincenzo Caracciolo, Riccardo Cerulli, Dmitry M. Chernyak, Fedor A. Danevich, Antonella Incicchitti, Dmytro V. Kasperovych, Vladislav V. Kobychev, Sergey I. Konovalov, Matthias Laubenstein, Vittorio Merlo, Francesco Montecchia, Oksana G. Polischuk, Denys V. Poda, Vladimir N. Shlegel, Vladimir I. Tretyak, Vladimir I. Umatov, Yan V. Vasiliev and Mykola M. Zarytskyy Show full author list Hide full author list

Universe 2018, 4(12), 147; https://doi.org/10.3390/universe4120147 - 14 Dec 2018

Cited by 2 | Viewed by 3738

Abstract

Recent developments, results, and perspectives arising from double beta decay experiments at the Gran Sasso National Laboratory (LNGS) of the INFN by using HPGe detectors and crystal scintillators and by exploiting various approaches and different isotopes are summarized. The measurements here presented have [...] Read more.

Recent developments, results, and perspectives arising from double beta decay experiments at the Gran Sasso National Laboratory (LNGS) of the INFN by using HPGe detectors and crystal scintillators and by exploiting various approaches and different isotopes are summarized. The measurements here presented have been performed in the experimental set-ups of the DAMA collaboration. These setups are optimized for low-background studies and operate deep underground at LNGS. The presented results are of significant value to the field, and the sensitivity achieved for some of the considered isotopes is one of the best available to date. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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8 pages, 1889 KiB

Open AccessArticle

Prospects for Heavy-Ion Physics with the MPD Detector at NICA

by Vadim Kolesnikov

Universe 2018, 4(12), 145; https://doi.org/10.3390/universe4120145 - 8 Dec 2018

Cited by 1 | Viewed by 2954

Abstract

The construction of the NICA accelerator facility is underway at Joint Institute for Nuclear Research (JINR) (Dubna, Russia). The main goal of the MPD experiment at NICA will be the experimental exploration of the Quantum Chromodynamics (QCD) phase structure at high baryon density. [...] Read more.

The construction of the NICA accelerator facility is underway at Joint Institute for Nuclear Research (JINR) (Dubna, Russia). The main goal of the MPD experiment at NICA will be the experimental exploration of the Quantum Chromodynamics (QCD) phase structure at high baryon density. In this article, the current status of the NICA/MPD project is presented. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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19 pages, 542 KiB

Open AccessArticle

Kappa Distributions: Statistical Physics and Thermodynamics of Space and Astrophysical Plasmas

by George Livadiotis

Universe 2018, 4(12), 144; https://doi.org/10.3390/universe4120144 - 7 Dec 2018

Cited by 21 | Viewed by 4366

Abstract

Kappa distributions received impetus as they provide efficient modelling of the observed particle distributions in space and astrophysical plasmas throughout the heliosphere. This paper presents (i) the connection of kappa distributions with statistical mechanics, by maximizing the associated q-entropy under the constraints [...] Read more.

Kappa distributions received impetus as they provide efficient modelling of the observed particle distributions in space and astrophysical plasmas throughout the heliosphere. This paper presents (i) the connection of kappa distributions with statistical mechanics, by maximizing the associated q-entropy under the constraints of the canonical ensemble within the framework of continuous description; (ii) the derivation of q-entropy from first principles that characterize space plasmas, the additivity of energy, and entropy; and (iii) the derivation of the characteristic first order differential equation, whose solution is the kappa distribution function. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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12 pages, 368 KiB

Open AccessArticle

Exotic Baryons in Chiral Soliton Models

by Herbert Weigel

Universe 2018, 4(12), 142; https://doi.org/10.3390/universe4120142 - 6 Dec 2018

Cited by 2 | Viewed by 3288

Abstract

We cautiously review the treatment of pentaquark exotic baryons in chiral soliton models. We consider two examples and argue that any consistent and self-contained description must go beyond the mean field approximation that only considers the classical soliton and the canonical quantization of [...] Read more.

We cautiously review the treatment of pentaquark exotic baryons in chiral soliton models. We consider two examples and argue that any consistent and self-contained description must go beyond the mean field approximation that only considers the classical soliton and the canonical quantization of its (would-be) zero modes via collective coordinates. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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9 pages, 886 KiB

Open AccessArticle

Analogies between the Black Hole Interior and the Type II Weyl Semimetals

by Mikhail Zubkov

Universe 2018, 4(12), 135; https://doi.org/10.3390/universe4120135 - 28 Nov 2018

Cited by 9 | Viewed by 3234

Abstract

In the Painleve–Gullstrand (PG) reference frame, the description of elementary particles in the background of a black hole (BH) is similar to the description of non-relativistic matter falling toward the BH center. The velocity of the fall depends on the distance to the [...] Read more.

In the Painleve–Gullstrand (PG) reference frame, the description of elementary particles in the background of a black hole (BH) is similar to the description of non-relativistic matter falling toward the BH center. The velocity of the fall depends on the distance to the center, and it surpasses the speed of light inside the horizon. Another analogy to non-relativistic physics appears in the description of the massless fermionic particle. Its Hamiltonian inside the BH, when written in the PG reference frame, is identical to the Hamiltonian of the electronic quasiparticles in type II Weyl semimetals (WSII) that reside in the vicinity of a type II Weyl point. When these materials are in the equilibrium state, the type II Weyl point becomes the crossing point of the two pieces of the Fermi surface called Fermi pockets. It was previously stated that there should be a Fermi surface inside a black hole in equilibrium. In real materials, type II Weyl points come in pairs, and the descriptions of the quasiparticles in their vicinities are, to a certain extent, inverse. Namely, the directions of their velocities are opposite. In line with the mentioned analogy, we propose the hypothesis that inside the equilibrium BH there exist low-energy excitations moving toward the exterior of the BH. These excitations are able to escape from the BH, unlike ordinary matter that falls to its center. The important consequences to the quantum theory of black holes follow. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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9 pages, 329 KiB

Open AccessArticle

Quantum Dynamics of Charged Fermions in the Wigner Formulation of Quantum Mechanics

by Vladimir Filinov and Alexander Larkin

Universe 2018, 4(12), 133; https://doi.org/10.3390/universe4120133 - 23 Nov 2018

Cited by 3 | Viewed by 2854

Abstract

To study the kinetic properties of dense quantum plasma, a new quantum dynamics method in the Wigner representation of quantum mechanics has been developed for extreme conditions, when analytical approximations based on different kinds of perturbation theories cannot be applied. This method combines [...] Read more.

To study the kinetic properties of dense quantum plasma, a new quantum dynamics method in the Wigner representation of quantum mechanics has been developed for extreme conditions, when analytical approximations based on different kinds of perturbation theories cannot be applied. This method combines the Feynman and Wigner formulation of quantum mechanics and uses for calculation the path integral Monte-Carlo (WPIMC) in phase space and quantum generalization of the classical molecular dynamics methods (WMD) allowing to solve the quantum Wigner–Liouville-like equation. The Fermi–Dirac statistical effects are accounted for by the effective pair pseudopotential depending on coordinates and momenta and allowing to avoid the famous “sign problem” due to realization of the Pauli blocking of fermions. Significant influence of the interparticle interaction on the high energy asymptotics of the momentum distribution functions have been observed. According to the quantum Kubo formula, we also study the electron conductivity of dense plasma media. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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15 pages, 573 KiB

Open AccessEditor’s ChoiceArticle

SU(2) Quantum Yang–Mills Thermodynamics: Some Theory and Some Applications

by Ralf Hofmann

Universe 2018, 4(12), 132; https://doi.org/10.3390/universe4120132 - 22 Nov 2018

Viewed by 6482

Abstract

In the first part of this talk, we review some prerequisites for and essential arguments involved in the construction of the thermal-ground-state estimate underlying the deconfining phase in the thermodynamics of SU(2) Quantum Yang–Mills theory and how this structure supports its distinct excitations. [...] Read more.

In the first part of this talk, we review some prerequisites for and essential arguments involved in the construction of the thermal-ground-state estimate underlying the deconfining phase in the thermodynamics of SU(2) Quantum Yang–Mills theory and how this structure supports its distinct excitations. The second part applies deconfining SU(2) Yang–Mills thermodynamics to the Cosmic Microwave Background in view of (i) a modified temperature-redshift relation with an interesting link to correlation-length criticality in the 3D Ising model, (ii) the implied minimal changes in the dark sector of the cosmological model, and (iii) best-fit parameter values of this model when confronted with the spectra of the angular two-point functions temperature-temperature (TT), temperature-E-mode-polarisation (TE), E-mode-polarisation-E-mode-polarisation (EE), excluding the low-l physics. The latter, which so far is treated in an incomplete way due to the omission of radiative effects, is addressed in passing. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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19 pages, 2888 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Collider Searches for Dark Matter (ATLAS + CMS)

by Nicolò Trevisani

Universe 2018, 4(11), 131; https://doi.org/10.3390/universe4110131 - 20 Nov 2018

Cited by 9 | Viewed by 4944

Abstract

Several searches for dark matter have been performed by the CMS and ATLAS collaborations, using proton-proton collisions with a center-of-mass energy of 13 TeV produced by the Large Hadron Collider. Different signatures may highlight the presence of dark matter: the imbalance in the [...] Read more.

Several searches for dark matter have been performed by the CMS and ATLAS collaborations, using proton-proton collisions with a center-of-mass energy of 13 TeV produced by the Large Hadron Collider. Different signatures may highlight the presence of dark matter: the imbalance in the transverse momentum in an event due to the presence of undetectable dark matter particles, produced together with one Standard Model particle, a bump in the di-jet or di-lepton invariant mass distributions, or an excess of events in the di-jet angular distribution, produced by a dark matter mediator. No significant discrepancies with respect to the Standard Model predictions have been found in data, so that limits on the dark matter couplings to ordinary matter, or limits on the dark matter particles and mediators masses have been set. The results are also re-interpreted as limits on the dark matter interaction cross-section with baryonic matter, so that a comparison with direct detection experiments is allowed. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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8 pages, 2455 KiB

Open AccessArticle

First Results on the Rare Decay K⁺ → π⁺νν from the NA62 Experiment at CERN

by Francesco Gonnella

Universe 2018, 4(11), 130; https://doi.org/10.3390/universe4110130 - 20 Nov 2018

Viewed by 2920

Abstract

The NA62 experiment at CERN Super Proton Synchrotron (SPS) is currently taking data to measure the ultra-rare decay

K^{+} \to π^{+} ν \bar{ν}

. This decay, whose Branching Ratio (BR) is predicted with high precision within the Standard Model (SM), [...] Read more.

The NA62 experiment at CERN Super Proton Synchrotron (SPS) is currently taking data to measure the ultra-rare decay

K^{+} \to π^{+} ν \bar{ν}

. This decay, whose Branching Ratio (BR) is predicted with high precision within the Standard Model (SM), is one of the best candidates to reveal the indirect effects of New Physics (NP) at the highest mass scales. The NA62 experiment is designed to measure BR (

K^{+} \to π^{+} ν \bar{ν})

with a decay-in-flight technique, novel for this channel. NA62 took data in 2016, 2017 and 2018; statistics collected in 2016 allows NA62 to reach the SM sensitivity for this decay, reaching the single event sensitivity (SES) and showing the proof of principle of the experiment. The preliminary result on BR (

K^{+} \to π^{+} ν \bar{ν})

from the analysis of the 2016 data set is described. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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12 pages, 2163 KiB

Open AccessArticle

The Pierre Auger Observatory: Review of Latest Results and Perspectives

by Dariusz Góra and For the Pierre Auger Collaboration

Universe 2018, 4(11), 128; https://doi.org/10.3390/universe4110128 - 17 Nov 2018

Cited by 7 | Viewed by 5063

Abstract

The Pierre Auger Observatory is the world’s largest operating detection system for the observation of ultra high energy cosmic rays (UHECRs), with energies above

10^{17}

eV. The detector allows detailed measurements of the energy spectrum, mass composition and arrival directions of primary [...] Read more.

The Pierre Auger Observatory is the world’s largest operating detection system for the observation of ultra high energy cosmic rays (UHECRs), with energies above

10^{17}

eV. The detector allows detailed measurements of the energy spectrum, mass composition and arrival directions of primary cosmic rays in the energy range above

10^{17}

eV. The data collected at the Auger Observatory over the last decade show the suppression of the cosmic ray flux at energies above

4 \times 10^{19}

eV. However, it is still unclear if this suppression is caused by the energy limitation of their sources or by the Greisen–Zatsepin–Kuzmin (GZK) cut-off. In such a case, UHECRs would interact with the microwave background (CMB), so that particles traveling long intergalactic distances could not have energies greater than

5 \times 10^{19}

eV. The other puzzle is the origin of UHECRs. Some clues can be drawn from studying the distribution of their arrival directions. The recently observed dipole anisotropy has an orientation that indicates an extragalactic origin of UHECRs. The Auger surface detector array is also sensitive to showers due to ultra high energy neutrinos of all flavors and photons, and recent neutrino and photon limits provided by the Auger Observatory can constrain models of the cosmogenic neutrino production and exotic scenarios of the UHECRs origin, such as the decays of super heavy, non-standard-model particles. In this paper, the recent results on measurements of the energy spectrum, mass composition and arrival directions of cosmic rays, as well as future prospects are presented. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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7 pages, 1471 KiB

Open AccessArticle

Neutrino Physics and Astrophysics with the JUNO Detector

by Lino Miramonti

Universe 2018, 4(11), 126; https://doi.org/10.3390/universe4110126 - 16 Nov 2018

Cited by 3 | Viewed by 4187

Abstract

The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton liquid scintillator multi-purpose underground detector, under construction near the Chinese city of Jiangmen, with data collection expected to start in 2021. The main goal of the experiment is the neutrino mass hierarchy determination, [...] Read more.

The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton liquid scintillator multi-purpose underground detector, under construction near the Chinese city of Jiangmen, with data collection expected to start in 2021. The main goal of the experiment is the neutrino mass hierarchy determination, with more than three sigma significance, and the high-precision neutrino oscillation parameter measurements, detecting electron anti-neutrinos emitted from two nearby (baseline of about 53 km) nuclear power plants. Besides, the unprecedented liquid scintillator-type detector performance in target mass, energy resolution, energy calibration precision, and low-energy threshold features a rich physics program for the detection of low-energy astrophysical neutrinos, such as galactic core-collapse supernova neutrinos, solar neutrinos, and geo-neutrinos. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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11 pages, 249 KiB

Open AccessArticle

QCD at High Energies and Yangian Symmetry

by Roland Kirschner

Universe 2018, 4(11), 124; https://doi.org/10.3390/universe4110124 - 13 Nov 2018

Cited by 1 | Viewed by 2626

Abstract

Yangian symmetric correlators provide a tool to investigate integrability features of QCD at high energies. We discuss the kernel of the equation of perturbative Regge asymptotics, the kernels of the evolution equation of parton distributions, Born scattering amplitudes and coupling renormalization. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

11 pages, 847 KiB

Open AccessArticle

Spacetime Continuity and Quantum Information Loss

by Michael R. R. Good

Universe 2018, 4(11), 122; https://doi.org/10.3390/universe4110122 - 9 Nov 2018

Cited by 23 | Viewed by 4316

Abstract

Continuity across the shock wave of two regions in the metric during the formation of a black hole can be relaxed in order to achieve information preservation. A Planck scale sized spacetime discontinuity leads to unitarity (a constant asymptotic entanglement entropy) by restricting [...] Read more.

Continuity across the shock wave of two regions in the metric during the formation of a black hole can be relaxed in order to achieve information preservation. A Planck scale sized spacetime discontinuity leads to unitarity (a constant asymptotic entanglement entropy) by restricting the origin of coordinates (moving mirror) to be timelike. Moreover, thermal equilibration occurs and total evaporation energy emitted is finite. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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8 pages, 277 KiB

Open AccessArticle

Total and Differential Cross Sections for Higgs and Top-Quark Production

by Nikolaos Kidonakis

Universe 2018, 4(11), 121; https://doi.org/10.3390/universe4110121 - 9 Nov 2018

Cited by 2 | Viewed by 2831

Abstract

I present theoretical calculations for Higgs-boson and top-quark production, including high-order soft-gluon corrections. I discuss charged-Higgs production in association with a top quark or a W boson, as well as single-top and top-antitop production. Total cross sections as well as transverse-momentum and rapidity [...] Read more.

I present theoretical calculations for Higgs-boson and top-quark production, including high-order soft-gluon corrections. I discuss charged-Higgs production in association with a top quark or a W boson, as well as single-top and top-antitop production. Total cross sections as well as transverse-momentum and rapidity distributions of the top quark or the Higgs boson are presented for various LHC energies. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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9 pages, 2257 KiB

Open AccessArticle

Supersymmetric and Conformal Features of Hadron Physics

by Stanley J. Brodsky

Universe 2018, 4(11), 120; https://doi.org/10.3390/universe4110120 - 8 Nov 2018

Cited by 2 | Viewed by 3468

Abstract

The QCD Lagrangian is based on quark and gluonic fields—not squarks nor gluinos. However, one can show that its hadronic eigensolutions conform to a representation of superconformal algebra, reflecting the underlying conformal symmetry of chiral QCD. The eigensolutions of superconformal algebra provide a [...] Read more.

The QCD Lagrangian is based on quark and gluonic fields—not squarks nor gluinos. However, one can show that its hadronic eigensolutions conform to a representation of superconformal algebra, reflecting the underlying conformal symmetry of chiral QCD. The eigensolutions of superconformal algebra provide a unified Regge spectroscopy of meson, baryon, and tetraquarks of the same parity and twist as equal-mass members of the same 4-plet representation with a universal Regge slope. The predictions from light-front holography and superconformal algebra can also be extended to mesons, baryons, and tetraquarks with strange, charm and bottom quarks. The pion

q \bar{q}

eigenstate has zero mass for

m_{q} = 0 .

A key tool is the remarkable observation of de Alfaro, Fubini, and Furlan (dAFF) which shows how a mass scale can appear in the Hamiltonian and the equations of motion while retaining the conformal symmetry of the action. When one applies the dAFF procedure to chiral QCD, a mass scale

κ

appears which determines universal Regge slopes, hadron masses in the absence of the Higgs coupling. One also predicts the form of the nonperturbative QCD running coupling:

α_{s} (Q^{2}) \propto e^{- Q^{2} / 4 κ^{2}}

, in agreement with the effective charge determined from measurements of the Bjorken sum rule. One also obtains viable predictions for spacelike and timelike hadronic form factors, structure functions, distribution amplitudes, and transverse momentum distributions. The combination of conformal symmetry, light-front dynamics, its holographic mapping to AdS

_{5}

space, and the dAFF procedure thus provide new insights, not only into the physics underlying color confinement, but also the nonperturbative QCD coupling and the QCD mass scale. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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10 pages, 2180 KiB

Open AccessArticle

Search for Exotic Particles at the NA62 Experiment

by Maria Brigida Brunetti, Francesco Gonnella, Lorenza Iacobuzio and On behalf of the NA62 Collaboration

Universe 2018, 4(11), 119; https://doi.org/10.3390/universe4110119 - 7 Nov 2018

Cited by 1 | Viewed by 3097

Abstract

The NA62 experiment at the CERN Super Proton Synchrotron (SPS) is currently taking data to measure the ultra-rare decay

K^{+} \to π^{+} ν \bar{ν}

. The high-intensity setup, trigger flexibility, detector performance and high-efficiency vetoes make NA62 also suitable for [...] Read more.

The NA62 experiment at the CERN Super Proton Synchrotron (SPS) is currently taking data to measure the ultra-rare decay

K^{+} \to π^{+} ν \bar{ν}

. The high-intensity setup, trigger flexibility, detector performance and high-efficiency vetoes make NA62 also suitable for direct searches of long-lived, beyond-the-Standard-Model particles, such as Heavy Neutral Leptons (HNLs), Axion-Like Particles (ALPs) and Dark Photons (DPs); moreover, many rare and forbidden decays are studied at NA62. The status of all these searches is reviewed, together with prospects for future data taking at NA62 after the CERN Long Shutdown 2 (LS2). Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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14 pages, 1045 KiB

Open AccessArticle

Solar Neutrinos Spectroscopy with Borexino Phase-II

by Lino Miramonti, Matteo Agostini, Konrad Altenmueller, Simon Appel, Victor Atroshchenko, Zara Bagdasarian, Davide Basilico, Gianpaolo Bellini, Jay Benziger, Daniel Bick, Irene Bolognino, Giuseppe Bonfini, David Bravo, Barbara Caccianiga, Frank Calaprice, Alessio Caminata, Silvia Caprioli, Marco Carlini, Paolo Cavalcante, Francesca Cavanna, Alexander Chepurnov, Koun Choi, Laura Collica, Stefano Davini, Alexander Derbin, XueFeng Ding, Antonio Di Ludovico, Lea Di Noto, Ilia Drachnev, Kirill Fomenko, Andrey Formozov, Davide Franco, Federico Gabriele, Cristiano Galbiati, Michael Gschwender, Chiara Ghiano, Marco Giammarchi, Augusto Goretti, Maxim Gromov, Daniele Guffanti, Caren Hagner, Thibaut Houdy, Ed Hungerford, Aldo Ianni, Andrea Ianni, Anna Jany, Dominik Jeschke, Vladislav Kobychev, Denis Korablev, Gyorgy Korga, Tobias Lachenmaier, Matthias Laubenstein, Evgeny Litvinovich, Francesco Lombardi, Paolo Lombardi, Livia Ludhova, Georgy Lukyanchenko, Liudmila Lukyanchenko, Igor Machulin, Giulio Manuzio, Simone Marcocci, Jelena Maricic, Johann Martyn, Emanuela Meroni, Mikko Meyer, Marcin Misiaszek, Valentina Muratova, Birgit Neumair, Lothar Oberauer, Bjoern Opitz, Vsevolod Orekhov, Fausto Ortica, Marco Pallavicini, Laszlo Papp, Omer Penek, Lidio Pietrofaccia, Nelly Pilipenko, Andrea Pocar, Alessio Porcelli, Georgy Raikov, Gioacchino Ranucci, Alessandro Razeto, Alessandra Re, Mariia Redchuk, Aldo Romani, Nicola Rossi, Sebastian Rottenanger, Stefan Schöenert, Dmitrii Semenov, Mikhail Skorokhvatov, Oleg Smirnov, Albert Sotnikov, Lee F. F. Stokes, Yura Suvorov, Roberto Tartaglia, Gemma Testera, Jan Thurn, Maria Toropova, Evgenii Unzhakov, Alina Vishneva, Bruce Vogelaar, Franz Von Feilitzsch, Stefan Weinz, Marcin Wojcik, Michael Wurm, Zachary Yokley, Oleg Zaimidoroga, Sandra Zavatarelli, Kai Zuber and Grzegorz Zuzel Show full author list Hide full author list

Universe 2018, 4(11), 118; https://doi.org/10.3390/universe4110118 - 7 Nov 2018

Cited by 2 | Viewed by 4886

Abstract

Solar neutrinos have played a central role in the discovery of the neutrino oscillation mechanism. They still are proving to be a unique tool to help investigate the fusion reactions that power stars and further probe basic neutrino properties. The Borexino neutrino observatory [...] Read more.

Solar neutrinos have played a central role in the discovery of the neutrino oscillation mechanism. They still are proving to be a unique tool to help investigate the fusion reactions that power stars and further probe basic neutrino properties. The Borexino neutrino observatory has been operationally acquiring data at Laboratori Nazionali del Gran Sasso in Italy since 2007. Its main goal is the real-time study of low energy neutrinos (solar or originated elsewhere, such as geo-neutrinos). The latest analysis of experimental data, taken during the so-called Borexino Phase-II (2011-present), will be showcased in this talk—yielding new high-precision, simultaneous wide band flux measurements of the four main solar neutrino components belonging to the “pp” fusion chain (pp, pep,

^{7}

Be,

^{8}

B), as well as upper limits on the remaining two solar neutrino fluxes (CNO and hep). Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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12 pages, 655 KiB

Open AccessArticle

Ions, Protons, and Photons as Signatures of Monopoles

by Vicente Vento

Universe 2018, 4(11), 117; https://doi.org/10.3390/universe4110117 - 7 Nov 2018

Cited by 6 | Viewed by 2895

Abstract

Magnetic monopoles have been a subject of interest since Dirac established the relationship between the existence of monopoles and charge quantization. The Dirac quantization condition bestows the monopole with a huge magnetic charge. The aim of this study was to determine whether this [...] Read more.

Magnetic monopoles have been a subject of interest since Dirac established the relationship between the existence of monopoles and charge quantization. The Dirac quantization condition bestows the monopole with a huge magnetic charge. The aim of this study was to determine whether this huge magnetic charge allows monopoles to be detected by the scattering of charged ions and protons on matter where they might be bound. We also analyze if this charge favors monopolium (monopole–antimonopole) annihilation into many photons over two photon decays. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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12 pages, 418 KiB

Open AccessArticle

First Model Independent Results from DAMA/LIBRA–Phase2

by Rita Bernabei, Pierluigi Belli, Andrea Bussolotti, Fabio Cappella, Vincenzo Caracciolo, Riccardo Cerulli, Chang-Jiang Dai, Annelisa D’Angelo, Alessandro Di Marco, Hui-Lin He, Antonella Incicchitti, Xin-Hua Ma, Angelo Mattei, Vittorio Merlo, Francesco Montecchia, Xiang-Dong Sheng and Zi-Piao Ye

Universe 2018, 4(11), 116; https://doi.org/10.3390/universe4110116 - 6 Nov 2018

Cited by 95 | Viewed by 6321

Abstract

The first results obtained by the DAMA/LIBRA–phase2 experiment are presented. The data have been collected over six independent annual cycles corresponding to a total exposure of 1.13 ton × year, deep underground at the Gran Sasso National Laboratory. The DAMA/LIBRA–phase2 apparatus, about 250 [...] Read more.

The first results obtained by the DAMA/LIBRA–phase2 experiment are presented. The data have been collected over six independent annual cycles corresponding to a total exposure of 1.13 ton × year, deep underground at the Gran Sasso National Laboratory. The DAMA/LIBRA–phase2 apparatus, about 250 kg highly radio-pure NaI(Tl), profits from a second generation high quantum efficiency photomultipliers and of new electronics with respect to DAMA/LIBRA–phase1. The improved experimental configuration has also allowed to lower the software energy threshold. The DAMA/LIBRA–phase2 data confirm the evidence of a signal that meets all the requirements of the model independent Dark Matter annual modulation signature, at 9.5

σ

C.L. in the energy region (1–6) keV. In the energy region between 2 and 6 keV, where data are also available from DAMA/NaI and DAMA/LIBRA–phase1, the achieved C.L. for the full exposure (2.46 ton × year) is 12.9

σ

. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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7 pages, 1001 KiB

Open AccessArticle

Cosmic-Ray Extremely Distributed Observatory: Status and Perspectives

by Dariusz Góra, Kevin Almeida Cheminant, David Alvarez-Castillo, Łukasz Bratek, Niraj Dhital, Alan R. Duffy, Piotr Homola, Pawel Jagoda, Joanna Jałocha, Marcin Kasztelan, Konrad Kopański, Peter Kovacs, Vahab Nazari, Michal Niedźwiecki, Dominik Ostrogórski, Karel Smołek, Jaroslaw Stasielak, Oleksander Sushchov, Krzysztof W. Woźniak and Jilberto Zamora-Saa

Universe 2018, 4(11), 111; https://doi.org/10.3390/universe4110111 - 24 Oct 2018

Cited by 13 | Viewed by 4117

Abstract

The Cosmic-Ray Extremely Distributed Observatory (CREDO) is a project dedicated to global studies of extremely extended cosmic-ray phenomena, the cosmic-ray ensembles (CRE), beyond the capabilities of existing detectors and observatories. Up to date, cosmic-ray research has been focused on detecting single air showers, [...] Read more.

The Cosmic-Ray Extremely Distributed Observatory (CREDO) is a project dedicated to global studies of extremely extended cosmic-ray phenomena, the cosmic-ray ensembles (CRE), beyond the capabilities of existing detectors and observatories. Up to date, cosmic-ray research has been focused on detecting single air showers, while the search for ensembles of cosmic-rays, which may overspread a significant fraction of the Earth, is a scientific terra incognita. Instead of developing and commissioning a completely new global detector infrastructure, CREDO proposes approaching the global cosmic-ray analysis objectives with all types of available detectors, from professional to pocket size, merged into a worldwide network. With such a network it is possible to search for evidences of correlated cosmic-ray ensembles. One of the observables that can be investigated in CREDO is a number of spatially isolated events collected in a small time window which could shed light on fundamental physics issues. The CREDO mission and strategy requires active engagement of a large number of participants, also non-experts, who will contribute to the project by using common electronic devices (e.g., smartphones). In this note, the status and perspectives of the project are presented. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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8 pages, 1878 KiB

Open AccessArticle

The Belle II Experiment: Status and Prospects

by Paolo Branchini

Universe 2018, 4(10), 101; https://doi.org/10.3390/universe4100101 - 1 Oct 2018

Cited by 2 | Viewed by 4009

Abstract

The Belle II experiment is a substantial upgrade of the Belle detector and will operate at the SuperKEKBenergy-asymmetric

e^{+} e^{-}

collider. The accelerator has already successfully completed the first phase of commissioning in 2016. The first electron versus positron collisions in [...] Read more.

The Belle II experiment is a substantial upgrade of the Belle detector and will operate at the SuperKEKBenergy-asymmetric

e^{+} e^{-}

collider. The accelerator has already successfully completed the first phase of commissioning in 2016. The first electron versus positron collisions in Belle II were delivered in April 2018. The design luminosity of SuperKEKB is 8 ×

10^{35}

cm⁻²s⁻¹, and the Belle II experiment aims to record 50 ab⁻¹ of data, a factor of 50 more than the Belle experiment. This large dataset will be accumulated with low backgrounds and high trigger efficiencies in a clean

e^{+} e^{-}

environment. This contribution will review the detector upgrade, the achieved detector performance and the plans for the commissioning of Belle II. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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Review

Jump to: Research, Other

16 pages, 1051 KiB

Open AccessReview

Hard-Core Radius of Nucleons within the Induced Surface Tension Approach

by Kyrill A. Bugaev, Aleksei I. Ivanytskyi, Violetta V. Sagun, Boris E. Grinyuk, Denis O. Savchenko, Gennady M. Zinovjev, Edward G. Nikonov, Larissa V. Bravina, Evgeny E. Zabrodin, David B. Blaschke, Arkadiy V. Taranenko and Ludwik Turko

Universe 2019, 5(2), 63; https://doi.org/10.3390/universe5020063 - 17 Feb 2019

Cited by 13 | Viewed by 3532

Abstract

We review the recent approach to model the hadronic and nuclear matter equations of state using the induced surface tension concept, which allows one to go far beyond the usual Van der Waals approximation. Since the obtained equations of state, classical and quantum, [...] Read more.

We review the recent approach to model the hadronic and nuclear matter equations of state using the induced surface tension concept, which allows one to go far beyond the usual Van der Waals approximation. Since the obtained equations of state, classical and quantum, are among the most successful ones in describing the properties of low density phases of strongly interacting matter, they set strong restrictions on the possible value of the hard-core radius of nucleons, which is widely used in phenomenological equations of state. We summarize the latest results obtained within this novel approach and perform a new detailed analysis of the hard-core radius of nucleons, which follows from hadronic and nuclear matter properties. Such an analysis allows us to find the most trustworthy range of its values: the hard-core radius of nucleons is 0.3–0.36 fm. A comparison with the phenomenology of neutron stars implies that the hard-core radius of nucleons has to be temperature and density dependent. Such a finding is supported when the eigenvolume of composite particles like hadrons originates from their fermionic substructure due to the Pauli blocking effect. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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10 pages, 3198 KiB

Open AccessReview

Topological Entanglement and Knots

by Sergey Mironov

Universe 2019, 5(2), 60; https://doi.org/10.3390/universe5020060 - 13 Feb 2019

Cited by 5 | Viewed by 3065

Abstract

We study the connection between quantum and topological entanglement. We present several of the simplest examples of topological systems that can simulate quantum entanglement. We also propose to use toric cobordisms as a code space for a quantum computer. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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8 pages, 320 KiB

Open AccessReview

Searching for Wormholes Beyond Horndeski Theories

by Victoria Volkova

Universe 2019, 5(2), 54; https://doi.org/10.3390/universe5020054 - 5 Feb 2019

Cited by 2 | Viewed by 2454

Abstract

We discuss whether it is possible to construct a stable, static, spherically symmetric Lorentzian wormhole in beyond Horndeski theory. The deep analogy between the cosmological bounce and wormhole scenarios is described in detail. We show explicitly that going beyond Horndeski enables one to [...] Read more.

We discuss whether it is possible to construct a stable, static, spherically symmetric Lorentzian wormhole in beyond Horndeski theory. The deep analogy between the cosmological bounce and wormhole scenarios is described in detail. We show explicitly that going beyond Horndeski enables one to evade the no-go theorem formulated for the wormholes in the general Horndeski case. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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11 pages, 562 KiB

Open AccessReview

A Pedagogical Introduction to the Lifshitz Regime

by Robert D. Pisarski, Vladimir V. Skokov and Alexei Tsvelik

Universe 2019, 5(2), 48; https://doi.org/10.3390/universe5020048 - 29 Jan 2019

Cited by 13 | Viewed by 3080

Abstract

We give an elementary and pedagogical review of the phase diagrams which are possible in quantum chromodynamics (QCD). Herein, emphasis is upon the appearance of a critical endpoint, where disordered and ordered phases meet. In many models, though, a Lifshitz point also arises. [...] Read more.

We give an elementary and pedagogical review of the phase diagrams which are possible in quantum chromodynamics (QCD). Herein, emphasis is upon the appearance of a critical endpoint, where disordered and ordered phases meet. In many models, though, a Lifshitz point also arises. At a Lifshitz point, three phases meet: disordered, ordered, and one in which spatially inhomogeneous phases arise. At the level of mean field theory, the appearance of a Lifshitz point does not dramatically affect the phase diagram. We argue, however, that fluctuations about the Lifshitz point are very strong in the infrared and significantly alter the phase diagram. We discuss at length the analogy to inhomogeneous polymers, where the Lifshitz regime produces a bicontinuous microemulsion. We briefly mention the possible relevance to the phase diagram of QCD. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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10 pages, 1033 KiB

Open AccessReview

Chiralspin Symmetry and Its Implications for QCD

by Leonid Glozman

Universe 2019, 5(1), 38; https://doi.org/10.3390/universe5010038 - 19 Jan 2019

Cited by 7 | Viewed by 2557

Abstract

In a local gauge-invariant theory with massless Dirac fermions, a symmetry of the Lorentz-invariant fermion charge is larger than a symmetry of the Lagrangian as a whole. While the Dirac Lagrangian exhibits only a chiral symmetry, the fermion charge operator is invariant under [...] Read more.

In a local gauge-invariant theory with massless Dirac fermions, a symmetry of the Lorentz-invariant fermion charge is larger than a symmetry of the Lagrangian as a whole. While the Dirac Lagrangian exhibits only a chiral symmetry, the fermion charge operator is invariant under a larger symmetry group,

S U (2 N_{F})

, that includes chiral transformations as well as

S U {(2)}_{C S}

chiralspin transformations that mix the right- and left-handed components of fermions. Consequently, a symmetry of the electric interaction, which is driven by the charge density, is larger than a symmetry of the magnetic interaction and of the kinetic term. This allows separating in some situations electric and magnetic contributions. In particular, in QCD, the chromo-magnetic interaction contributes only to the near-zero modes of the Dirac operator, while confining chromo-electric interaction contributes to all modes. At high temperatures, above the chiral restoration crossover, QCD exhibits approximate

S U {(2)}_{C S}

and

S U (2 N_{F})

symmetries that are incompatible with free deconfined quarks. Consequently, elementary objects in QCD in this regime are quarks with a definite chirality bound by the chromo-electric field, without the chromo-magnetic effects. In this regime, QCD can be described as a stringy fluid. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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20 pages, 381 KiB

Open AccessReview

Inflation from Supersymmetry Breaking

by Ignatios Antoniadis

Universe 2019, 5(1), 30; https://doi.org/10.3390/universe5010030 - 16 Jan 2019

Cited by 2 | Viewed by 3097

Abstract

I discuss the possibility that inflation is driven by supersymmetry breaking, with the superpartner of the goldstino (sgoldstino) playing the role of the inflaton. Imposing an R-symmetry to satisfy the slow-roll conditions, avoiding the so-called

η

-problem, leads to an interesting class of [...] Read more.

I discuss the possibility that inflation is driven by supersymmetry breaking, with the superpartner of the goldstino (sgoldstino) playing the role of the inflaton. Imposing an R-symmetry to satisfy the slow-roll conditions, avoiding the so-called

η

-problem, leads to an interesting class of small field inflation models, characterised by an inflationary plateau around the maximum of scalar potential near the origin, where R-symmetry is restored with the inflaton rolling down to a minimum, describing the present phase of the Universe. Inflation can be driven by either an F- or a D-term, while the minimum has a positive tuneable vacuum energy. The models agree with cosmological observations and, in the simplest case, predict a rather small tensor-to-scalar ratio of primordial perturbations. This talk is an extended version of an earlier review (Antoniadis, 2018). Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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10 pages, 400 KiB

Open AccessReview

Feynman Rules, Ward Identities and Loop Corrections in Very Special Relativity Standard Model

by Jorge Alfaro

Universe 2019, 5(1), 16; https://doi.org/10.3390/universe5010016 - 4 Jan 2019

Cited by 10 | Viewed by 3586

Abstract

In this paper, we want to study one loop corrections in Very Special Relativity Standard Model(VSRSM). In order to satisfy the Ward identities and the

S i m (2)

symmetry of the model, we have to specify the Feynman rules, including [...] Read more.

In this paper, we want to study one loop corrections in Very Special Relativity Standard Model(VSRSM). In order to satisfy the Ward identities and the

S i m (2)

symmetry of the model, we have to specify the Feynman rules, including the infrared regulator. To do this, we adapt the Mandelstam–Leibbrandt (ML) prescription to incorporate external momentum-dependent null vectors. As an example, we use the new

S i m (2)

invariant dimensional regularization to compute one loop corrections to the effective action in the subsector of the VSRSM that describe the interaction of photons with charged leptons. New stringent bounds for the masses of

ν_{e}

and

ν_{μ}

are obtained. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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6 pages, 3773 KiB

Open AccessReview

Measurement of the Hadronic Resonance Production with ALICE at the CERN LHC

by Maria Vasileiou On behalf of the ALICE Collaboration

Universe 2019, 5(1), 6; https://doi.org/10.3390/universe5010006 - 26 Dec 2018

Viewed by 2478

Abstract

We present a comprehensive study of hadronic resonance production in pp, p-Pb and Pb-Pb collisions at different Large Hadron Collider (LHC) energies. In particular, the production of hadronic resonances, such as ρ(770)⁰, Κ*(892)⁰, φ(1020), Σ(1385)^±, Λ(1520) [...] Read more.

We present a comprehensive study of hadronic resonance production in pp, p-Pb and Pb-Pb collisions at different Large Hadron Collider (LHC) energies. In particular, the production of hadronic resonances, such as ρ(770)⁰, Κ*(892)⁰, φ(1020), Σ(1385)^±, Λ(1520) and Ξ(1530)⁰ will be discussed in detail. In heavy-ion collisions, hadronic resonances are sensitive to the re-scattering and regeneration processes occurring between chemical freeze-out and kinetic freeze-out due to their short lifetimes. The measurements in pp and p-Pb collisions are used as a reference for heavy-ion collisions and to search for the onset of collective phenomena. We will report on the transverse momentum spectra, integrated yields, mean transverse momenta, particle ratios and nuclear modification factors of hadronic resonances. The results will be compared to those of other experiments, and to theoretical models and Monte Carlo generators. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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22 pages, 356 KiB

Open AccessReview

Spontaneous CPT Violation and Quantum Anomalies in a Model for Matter–Antimatter Asymmetry in the Cosmos

by Nick E. Mavromatos and Sarben Sarkar

Universe 2019, 5(1), 5; https://doi.org/10.3390/universe5010005 - 25 Dec 2018

Cited by 22 | Viewed by 3388

Abstract

We review scenarios of baryogenesis through leptogenesis at early epochs of the universe, in string-inspired minimal extensions of the Standard Model (SM), involving heavy right-handed Majorana neutrinos. Spontaneous violation of CPT symmetry is induced by appropriate (in general, temperature-dependent) backgrounds of the Kalb–Ramond [...] Read more.

We review scenarios of baryogenesis through leptogenesis at early epochs of the universe, in string-inspired minimal extensions of the Standard Model (SM), involving heavy right-handed Majorana neutrinos. Spontaneous violation of CPT symmetry is induced by appropriate (in general, temperature-dependent) backgrounds of the Kalb–Ramond (KR) axion field, which has its origins in the (bosonic) massless string multiplet. As interesting features of the model, we also discuss two issues associated with quantum (chiral) anomalies: (i) the non-contribution of the KR axion background to the (anomalous) chiral magnetic effect, which arises in the presence of external electromagnetic fields and non-zero chiral chemical potentials of charged fermions; and (ii) the potential role of quantum fluctuations of the KR axion on the (anomalous) radiative generation of a Majorana mass for the right-handed neutrinos themselves. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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14 pages, 583 KiB

Open AccessReview

Precision Determination of α_s from Lattice QCD

by Mattia Dalla Brida

Universe 2018, 4(12), 148; https://doi.org/10.3390/universe4120148 - 15 Dec 2018

Cited by 5 | Viewed by 2905

Abstract

We present an overview of the recent lattice determination of the QCD coupling

α_{s}

by the ALPHA Collaboration. The computation is based on the non-perturbative determination of the

Λ

-parameter of N_f

= 3

QCD, and the perturbative matching of the [...] Read more.

We present an overview of the recent lattice determination of the QCD coupling

α_{s}

by the ALPHA Collaboration. The computation is based on the non-perturbative determination of the

Λ

-parameter of N_f

= 3

QCD, and the perturbative matching of the N_f

= 3

and N_f

= 5

theories. The final result:

α_{s} (m_{Z}) = 0.11852 (84)

, reaches sub-percent accuracy. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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10 pages, 251 KiB

Open AccessReview

Momentum Space Topology and Non-Dissipative Currents ^†

by Mikhail Zubkov, Zakhar Khaidukov and Ruslan Abramchuk

Universe 2018, 4(12), 146; https://doi.org/10.3390/universe4120146 - 12 Dec 2018

Cited by 8 | Viewed by 2676

Abstract

Relativistic heavy ion collisions represent an arena for the probe of various anomalous transport effects. Those effects, in turn, reveal the correspondence between the solid state physics and the high energy physics, which share the common formalism of quantum field theory. It may [...] Read more.

Relativistic heavy ion collisions represent an arena for the probe of various anomalous transport effects. Those effects, in turn, reveal the correspondence between the solid state physics and the high energy physics, which share the common formalism of quantum field theory. It may be shown that for the wide range of field–theoretic models, the response of various nondissipative currents to the external gauge fields is determined by the momentum space topological invariants. Thus, the anomalous transport appears to be related to the investigation of momentum space topology—the approach developed earlier mainly in the condensed matter theory. Within this methodology we analyse systematically the anomalous transport phenomena, which include, in particular, the anomalous quantum Hall effect, the chiral separation effect, the chiral magnetic effect, the chiral vortical effect and the rotational Hall effect. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

10 pages, 604 KiB

Open AccessReview

Results from the OPERA Experiment in the CNGS Beam

by Alessandro Paoloni and On Behalf of OPERA Collaboration

Universe 2018, 4(12), 143; https://doi.org/10.3390/universe4120143 - 7 Dec 2018

Viewed by 3110

Abstract

The OPERA experiment was designed to observe

ν_{μ} \to ν_{τ}

oscillations through

τ

appearance on the CERN Neutrino to Gran Sasso (CNGS) beam over a baseline of 730 km. OPERA was a hybrid experiment composed of lead plates and emulsion layers [...] Read more.

The OPERA experiment was designed to observe

ν_{μ} \to ν_{τ}

oscillations through

τ

appearance on the CERN Neutrino to Gran Sasso (CNGS) beam over a baseline of 730 km. OPERA was a hybrid experiment composed of lead plates and emulsion layers acting as a target for neutrino interactions. The experiment was complemented with electronic detectors: scintillator strips used as Target Trackers and muon spectrometers. A review of the OPERA final results is presented in this paper. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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12 pages, 462 KiB

Open AccessReview

Quantum No-Scale Regimes and String Moduli

by Hervé Partouche

Universe 2018, 4(11), 123; https://doi.org/10.3390/universe4110123 - 10 Nov 2018

Cited by 8 | Viewed by 3055

Abstract

We review that in no-scale models in perturbative string theory, flat, homogeneous and isotropic cosmological evolutions found at the quantum level can enter into “quantum no-scale regimes” (QNSRs). When this is the case, the quantum effective potential is dominated by the classical kinetic [...] Read more.

We review that in no-scale models in perturbative string theory, flat, homogeneous and isotropic cosmological evolutions found at the quantum level can enter into “quantum no-scale regimes” (QNSRs). When this is the case, the quantum effective potential is dominated by the classical kinetic energies of the no-scale modulus, dilaton and moduli not involved in the supersymmetry breaking. As a result, the evolutions approach the classical ones, where the no-scale structure is exact. When the one-loop potential is positive, a global attractor mechanism forces the initially expanding solutions to enter the QNSR describing a flat, ever-expanding universe. On the contrary, when the potential can reach negative values, the internal moduli induce in most cases some kind of instability of the growing universe. The latter stops expanding and eventually collapses, unless the initial conditions are tuned in a tiny region of the phase space. Finally, in QNSR, no gauge instability takes place, regardless of the details of the potential. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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Jump to: Research, Review

10 pages, 1913 KiB

Open AccessConference Report

Spontaneous μ-τ Reflection Symmetry Breaking in Neutrino Phenomenology

by Guo-Yuan Huang, Zhi-Zhong Xing and Jing-Yu Zhu

Universe 2018, 4(12), 141; https://doi.org/10.3390/universe4120141 - 4 Dec 2018

Cited by 3 | Viewed by 2569

Abstract

The latest global analysis of neutrino oscillation data indicates that the normal neutrino mass ordering is favored over the inverted one at the

3 σ

level. The best-fit values of the largest neutrino mixing angle

θ_{23}^{}

and the Dirac CP-violating phase [...] Read more.

The latest global analysis of neutrino oscillation data indicates that the normal neutrino mass ordering is favored over the inverted one at the

3 σ

level. The best-fit values of the largest neutrino mixing angle

θ_{23}^{}

and the Dirac CP-violating phase

δ

are located in the higher octant and the third quadrant, respectively. We show that these experimental trends can be naturally explained by the

μ

-

τ

reflection symmetry breaking, triggered by the one-loop renormalization-group equations (RGEs) running from a superhigh energy scale down to the electroweak scale in the framework of the minimal supersymmetric standard model (MSSM). The complete parameter space is numerically explored for both the Majorana and Dirac cases, by allowing the smallest neutrino mass

m_{1}^{}

and the MSSM parameter

tan β

to vary within their reasonable ranges. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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11 pages, 2142 KiB

Open AccessConference Report

Large High-Efficiency Thermal Neutron Detectors Based on the Micromegas Technology

by Georgios Tsiledakis, Alain Delbart, Daniel Desforge, Ioanis Giomataris, Thomas Papaevangelou, Richard Hall-Wilton, Carina Höglund, Linda Robinson, Susann Schmidt, Alain Menelle and Michal Pomorski

Universe 2018, 4(12), 134; https://doi.org/10.3390/universe4120134 - 28 Nov 2018

Cited by 1 | Viewed by 3778

Abstract

Due to the so-called ³He shortage crisis, many detection techniques for thermal neutrons are currently based on alternative converters. There are several possible ways of increasing the detection efficiency for thermal neutrons using the solid neutron-to-charge converters ¹⁰B or ¹⁰B [...] Read more.

Due to the so-called ³He shortage crisis, many detection techniques for thermal neutrons are currently based on alternative converters. There are several possible ways of increasing the detection efficiency for thermal neutrons using the solid neutron-to-charge converters ¹⁰B or ¹⁰B₄C. Here, we present an investigation of the Micromegas technology. The micro-pattern gaseous detector Micromegas was developed in the past years at Saclay and is now used in a wide variety of neutron experiments due to its combination of high accuracy, high rate capability, excellent timing properties, and robustness. A large high-efficiency Micromegas-based neutron detector is proposed for thermal neutron detection, containing several layers of ¹⁰B₄C coatings that are mounted inside the gas volume. The principle and the fabrication of a single detector unit prototype with overall dimension of ~15 × 15 cm² and its possibility to modify the number of ¹⁰B₄C neutron converter layers are described. We also report results from measurements that are verified by simulations, demonstrating that typically five ¹⁰B₄C layers of 1–2 μm thickness would lead to a detection efficiency of 20% for thermal neutrons and a spatial resolution of sub-mm. The high potential of this novel technique is given by the design being easily adapted to large sizes by constructing a mosaic of several such detector units, resulting in a large area coverage and high detection efficiencies. An alternative way of achieving this is to use a multi-layered Micromegas that is equipped with two-side ¹⁰B₄C-coated gas electron multiplier (GEM)-type meshes, resulting in a robust and large surface detector. Another innovative and very promising concept for cost-effective, high-efficiency, large-scale neutron detectors is by stacking ¹⁰B₄C-coated microbulk Micromegas. A prototype was designed and built, and the tests so far look very encouraging. Full article

(This article belongs to the Special Issue Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018))

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