Special Issue "Selected Papers from the 7th International Conference on New Frontiers in Physics (ICNFP 2018)"

A special issue of Universe (ISSN 2218-1997).

Deadline for manuscript submissions: closed (31 December 2018).

Special Issue Editors

Prof. Dr. Yakir Aharonov
Website
Guest Editor
1. Schmid College of Science, Chapman University, Orange, CA 92866, USA
2. School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel
Interests: quantum physics
Prof. Dr. David Blaschke
Website
Guest Editor
1. Institute of Theoretical Physics, University of Wroclaw, 50-204 Wroclaw, Poland
2. Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna, Russia
3. National Research Nuclear University (MEPhI), 115409 Moscow, Russia
Interests: quantum field theory; quantum statistics; quark gluon plasma; heavy ion collisions; compact stars
Special Issues and Collections in MDPI journals
Prof. Dr. Larissa Bravina
Website
Guest Editor
Department of Physics, Universitetet i Oslo, Oslo, Norway
Interests: theory of relativistic heavy ion collisions; high energy particle physics; computational physics
Prof. Dr. Sonia Kabana

Guest Editor
University of Nantes and SUBATECH, Nantes, France
Interests: Experimental particle and nuclear physics at high energy accelerators
Dr. Victoria Volkova

Guest Editor
Lomonosov Moscow State University, Department of Particle Physics and Cosmology, Moscow, Russian

Special Issue Information

Dear Colleagues,

This Special Issue will gather together works presented at the conference "New Frontiers in Physics” held in 2018, and aims to promote interdisciplinarity and the cross-fertilization of ideas between different disciplines addressing fundamental physics. The main topics of the Special Issue are particle physics, heavy ion physics, quantum optics and quantum information, astroparticle physics

Prof. Dr. Yakir Aharonov
Prof. Dr. David Blaschke
Prof. Dr. Larissa Bravina
Prof. Dr. Sonia Kabana
Dr. Victoria Volkova
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Universe is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • High Energy Particle Physics
  • Heavy Ion Collisions and Critical Phenomena
  • Quantum Physics, Quantum Optics and Quantum Information
  • Cosmology, Astrophysics, Gravity, Mathematical Physics

Published Papers (80 papers)

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Open AccessCommunication
Recent Results from LUX and Prospects for Dark Matter Searches with LZ
Universe 2019, 5(3), 73; https://doi.org/10.3390/universe5030073 - 07 Mar 2019
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
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Open AccessArticle
A New Approach to Calorimetry in Space-Based Experiments for High-Energy Cosmic Rays
Universe 2019, 5(3), 72; https://doi.org/10.3390/universe5030072 - 07 Mar 2019
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
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Open AccessArticle
Directed Flow in Microscopic Models in Relativistic A+A Collisions
Universe 2019, 5(3), 69; https://doi.org/10.3390/universe5030069 - 05 Mar 2019
Cited by 3
Abstract
Evolution of directed flow of charged particles produced in relativistic heavy-ion collisions at energies 4 s 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 s 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
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Open AccessCommunication
ANTARES and KM3NeT: The Latest Results of the Neutrino Telescopes in the Mediterranean
Universe 2019, 5(2), 65; https://doi.org/10.3390/universe5020065 - 21 Feb 2019
Cited by 2
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
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Open AccessArticle
Particle Production at High Energy: DGLAP, BFKL and Beyond
Universe 2019, 5(2), 64; https://doi.org/10.3390/universe5020064 - 20 Feb 2019
Cited by 1
Abstract
Particle production in high energy hadronic/nuclear collisions in the Bjorken limit Q 2 , s 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 , s 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 s , 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
Open AccessArticle
Two Types of Jets and Quark and Chromon Model in QCD
Universe 2019, 5(2), 62; https://doi.org/10.3390/universe5020062 - 14 Feb 2019
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
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Open AccessCommunication
Bayesian Analysis for Extracting Properties of the Nuclear Equation of State from Observational Data Including Tidal Deformability from GW170817
Universe 2019, 5(2), 61; https://doi.org/10.3390/universe5020061 - 14 Feb 2019
Cited by 11
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
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Open AccessArticle
The Investigation on the Dark Sector at the PADME Experiment
Universe 2019, 5(2), 59; https://doi.org/10.3390/universe5020059 - 12 Feb 2019
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
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Open AccessArticle
Weak Values and Two-State Vector Formalism in Elementary Scattering and Reflectivity—A New Effect
Universe 2019, 5(2), 58; https://doi.org/10.3390/universe5020058 - 12 Feb 2019
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
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Open AccessCommunication
Searches for Electric Dipole Moments—Overview of Status and New Experimental Efforts
Universe 2019, 5(2), 56; https://doi.org/10.3390/universe5020056 - 09 Feb 2019
Cited by 1
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
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Open AccessArticle
Highlights from GERDA: Probing the Majorana Neutrino Mass at 100 meV
Universe 2019, 5(2), 55; https://doi.org/10.3390/universe5020055 - 07 Feb 2019
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
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Open AccessCommunication
Mathematical Formulation of the No-Go Theorem in Horndeski Theory
Universe 2019, 5(2), 52; https://doi.org/10.3390/universe5020052 - 02 Feb 2019
Cited by 3
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
Open AccessArticle
An Accelerating Universe without Lambda: Delta Gravity Using Monte Carlo
Universe 2019, 5(2), 51; https://doi.org/10.3390/universe5020051 - 01 Feb 2019
Cited by 2
Abstract
A gravitational field model based on two symmetric tensors, g μ ν and 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 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 ( δ ˜ symmetry). We call them 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 ± 1.63 km/(s Mpc). This value is in concordance with the last measurement of the H 0 local value, 73.83 ± 1.48 km/(s Mpc). Full article
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Open AccessArticle
Mass Gap in Nonperturbative Quantization à La Heisenberg
Universe 2019, 5(2), 50; https://doi.org/10.3390/universe5020050 - 31 Jan 2019
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
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Open AccessCommunication
The ICARUS Experiment
Universe 2019, 5(2), 49; https://doi.org/10.3390/universe5020049 - 29 Jan 2019
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 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
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Open AccessCommunication
The MoEDAL Experiment at the LHC—A Progress Report
Universe 2019, 5(2), 47; https://doi.org/10.3390/universe5020047 - 29 Jan 2019
Cited by 4
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
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Open AccessArticle
Symmetry Constrained Decoherence of Conditional Expectation Values
Universe 2019, 5(2), 46; https://doi.org/10.3390/universe5020046 - 24 Jan 2019
Cited by 1
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
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Open AccessCommunication
Quantum Measurements in a Finite Space–Time Domain
Universe 2019, 5(2), 45; https://doi.org/10.3390/universe5020045 - 24 Jan 2019
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
Open AccessCommunication
The Current Status of the Fermilab Muon g–2 Experiment
Universe 2019, 5(2), 43; https://doi.org/10.3390/universe5020043 - 23 Jan 2019
Cited by 1
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
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Open AccessCommunication
Hamiltonian Approach to QCD at Finite Temperature
Universe 2019, 5(2), 40; https://doi.org/10.3390/universe5020040 - 22 Jan 2019
Cited by 1
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 S 1 ( [...] 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 ) × 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
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Open AccessArticle
Passive Advection of a Vector Field by Compressible Turbulent Flow: Renormalizations Group Analysis near d = 4
Universe 2019, 5(1), 37; https://doi.org/10.3390/universe5010037 - 18 Jan 2019
Cited by 1
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
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Open AccessArticle
Computing Neutron Capture Rates in Neutron-Degenerate Matter
Universe 2019, 5(1), 36; https://doi.org/10.3390/universe5010036 - 18 Jan 2019
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
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Open AccessArticle
Muon Radiography of Ancient Mines: The San Silvestro Archaeo-Mining Park (Campiglia Marittima, Tuscany)
Universe 2019, 5(1), 34; https://doi.org/10.3390/universe5010034 - 17 Jan 2019
Cited by 5
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
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Open AccessArticle
Entanglement and Disordered-Enhanced Topological Phase in the Kitaev Chain
Universe 2019, 5(1), 33; https://doi.org/10.3390/universe5010033 - 17 Jan 2019
Cited by 2
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
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Open AccessCommunication
The ATLAS Fast TracKer—Architecture, Status and High-Level Data Quality Monitoring Framework
Universe 2019, 5(1), 32; https://doi.org/10.3390/universe5010032 - 16 Jan 2019
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
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Open AccessCommunication
Highlights from the Compact Muon Solenoid (CMS) Experiment
Universe 2019, 5(1), 28; https://doi.org/10.3390/universe5010028 - 16 Jan 2019
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 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
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Open AccessCommunication
Experimental Limiting Factors for the Search of μ at Future Facilities
Universe 2019, 5(1), 27; https://doi.org/10.3390/universe5010027 - 15 Jan 2019
Abstract
The search for the Lepton Flavor Violating decay μ 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 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 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
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Open AccessArticle
On Quantum Fields at High Temperature
Universe 2019, 5(1), 26; https://doi.org/10.3390/universe5010026 - 15 Jan 2019
Cited by 1
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
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Open AccessArticle
Upgrade of the NA61/SHINE Facility beyond 2020 for an Expanded Physics Programme
Universe 2019, 5(1), 24; https://doi.org/10.3390/universe5010024 - 10 Jan 2019
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
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Open AccessArticle
μCosmics: A Low-Cost Educational Cosmic Ray Telescope
Universe 2019, 5(1), 23; https://doi.org/10.3390/universe5010023 - 10 Jan 2019
Cited by 4
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
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Open AccessCommunication
Latest Results from the T2K Neutrino Experiment
Universe 2019, 5(1), 21; https://doi.org/10.3390/universe5010021 - 09 Jan 2019
Cited by 1
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 × 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 × 10 21 protons on target. Results for oscillation parameters, including the CP violation parameter and neutrino mass ordering, are shown. Full article
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Open AccessCommunication
Highlight Talk from Super-Kamiokande
Universe 2019, 5(1), 20; https://doi.org/10.3390/universe5010020 - 09 Jan 2019
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
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Open AccessCommunication
Single-Top Quark Production at CMS
Universe 2019, 5(1), 19; https://doi.org/10.3390/universe5010019 - 09 Jan 2019
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
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Open AccessCommunication
Overview of the CMS Detector Performance at LHC Run 2
Universe 2019, 5(1), 18; https://doi.org/10.3390/universe5010018 - 09 Jan 2019
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
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Open AccessCommunication
Atmospheric Neutrino Search in the ICARUS T600 Detector
Universe 2019, 5(1), 17; https://doi.org/10.3390/universe5010017 - 09 Jan 2019
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
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Open AccessArticle
Strongly Intensive Observables in the Model with String Fusion
Universe 2019, 5(1), 15; https://doi.org/10.3390/universe5010015 - 04 Jan 2019
Cited by 1
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
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Open AccessArticle
Open Charm Measurements at CERN SPS Energies with the New Vertex Detector of the NA61/SHINE Experiment: Status and Plans
Universe 2019, 5(1), 14; https://doi.org/10.3390/universe5010014 - 04 Jan 2019
Cited by 1
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 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
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Open AccessArticle
Physical Justifications and Possible Astrophysical Manifestations of the Projective Theory of Relativity
Universe 2019, 5(1), 13; https://doi.org/10.3390/universe5010013 - 04 Jan 2019
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
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Open AccessArticle
The Gravothermal Instability at All Scales: From Turnaround Radius to Supernovae
Universe 2019, 5(1), 12; https://doi.org/10.3390/universe5010012 - 03 Jan 2019
Cited by 7
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
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Open AccessCommunication
The LUCID Detector for LHC Run-2
Universe 2019, 5(1), 11; https://doi.org/10.3390/universe5010011 - 03 Jan 2019
Cited by 1
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
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Open AccessCommunication
Four Loop Scalar ϕ4 Theory Using the Functional Renormalization Group
Universe 2019, 5(1), 9; https://doi.org/10.3390/universe5010009 - 02 Jan 2019
Cited by 2
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
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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
Universe 2019, 5(1), 10; https://doi.org/10.3390/universe5010010 - 02 Jan 2019
Cited by 2
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 · 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 ± 0.1 ( stat . ) ± 0.2 ( syst . ) ] × 10 20 yr which is the most precise measurement of the half-life and compatible with previous results. Full article
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Open AccessCommunication
Search for Neutrinos in Super-Kamiokande Associated with Gravitational Wave Events
Universe 2019, 5(1), 7; https://doi.org/10.3390/universe5010007 - 29 Dec 2018
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 ± 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 ± 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
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Open AccessArticle
Hellenic Lyceum Cosmic Observatories Network: Status Report and Outreach Activities
Universe 2019, 5(1), 4; https://doi.org/10.3390/universe5010004 - 22 Dec 2018
Cited by 5
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
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Open AccessArticle
Hybrid Detection of High Energy Showers in Urban Environments
Universe 2019, 5(1), 3; https://doi.org/10.3390/universe5010003 - 22 Dec 2018
Cited by 4
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
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Open AccessCommunication
Result on the Neutrinoless Double Beta Decay Search of 82Se with the CUPID-0 Experiment
Universe 2019, 5(1), 2; https://doi.org/10.3390/universe5010002 - 22 Dec 2018
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 × 10 24 year at 90% C.I. Full article
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Open AccessCommunication
Recent Developments and Results on Double Beta Decays with Crystal Scintillators and HPGe Spectrometry
Universe 2018, 4(12), 147; https://doi.org/10.3390/universe4120147 - 14 Dec 2018
Cited by 1
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
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Prospects for Heavy-Ion Physics with the MPD Detector at NICA
Universe 2018, 4(12), 145; https://doi.org/10.3390/universe4120145 - 08 Dec 2018
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
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Kappa Distributions: Statistical Physics and Thermodynamics of Space and Astrophysical Plasmas
Universe 2018, 4(12), 144; https://doi.org/10.3390/universe4120144 - 07 Dec 2018
Cited by 4
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
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Exotic Baryons in Chiral Soliton Models
Universe 2018, 4(12), 142; https://doi.org/10.3390/universe4120142 - 06 Dec 2018
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
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Analogies between the Black Hole Interior and the Type II Weyl Semimetals
Universe 2018, 4(12), 135; https://doi.org/10.3390/universe4120135 - 28 Nov 2018
Cited by 2
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
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Quantum Dynamics of Charged Fermions in the Wigner Formulation of Quantum Mechanics
Universe 2018, 4(12), 133; https://doi.org/10.3390/universe4120133 - 23 Nov 2018
Cited by 3
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
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First Results on the Rare Decay K+π+νν from the NA62 Experiment at CERN
Universe 2018, 4(11), 130; https://doi.org/10.3390/universe4110130 - 20 Nov 2018
Abstract
The NA62 experiment at CERN Super Proton Synchrotron (SPS) is currently taking data to measure the ultra-rare decay K + π + ν 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 + π + ν 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 + π + ν 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 + π + ν ν ¯ ) from the analysis of the 2016 data set is described. Full article
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The Pierre Auger Observatory: Review of Latest Results and Perspectives
Universe 2018, 4(11), 128; https://doi.org/10.3390/universe4110128 - 17 Nov 2018
Cited by 3
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 × 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 × 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
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Neutrino Physics and Astrophysics with the JUNO Detector
Universe 2018, 4(11), 126; https://doi.org/10.3390/universe4110126 - 16 Nov 2018
Cited by 2
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
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QCD at High Energies and Yangian Symmetry
Universe 2018, 4(11), 124; https://doi.org/10.3390/universe4110124 - 13 Nov 2018
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
Open AccessArticle
Spacetime Continuity and Quantum Information Loss
Universe 2018, 4(11), 122; https://doi.org/10.3390/universe4110122 - 09 Nov 2018
Cited by 8
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
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Total and Differential Cross Sections for Higgs and Top-Quark Production
Universe 2018, 4(11), 121; https://doi.org/10.3390/universe4110121 - 09 Nov 2018
Cited by 2
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
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Supersymmetric and Conformal Features of Hadron Physics
Universe 2018, 4(11), 120; https://doi.org/10.3390/universe4110120 - 08 Nov 2018
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 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 ) 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.