Search Results (4)

A design study ESSνSB was carried out during the years 2018–2021 concerning how the five MW linear proton accelerators of the European Spallation Source, which are currently under construction in Lund, Sweden, can be used to generate a world-unique, intense neutrino Super Beam for precision measurements of the leptonic CP violating phase δ_CP. As there are definite limits, which are related to uncertainties in neutrino–nucleus interaction modeling, to how far the systematic errors in such measurements can be reduced, the method chosen in this project is to make the measurements at the second oscillation maximum, where the CP violation signal is close to three times larger than at the first, whereas the systematic errors are approximately the same at the two maxima. As the second maximum is located three times further away from the neutrino source than the first maximum, a higher neutrino beam intensity and thus a higher proton driver power are required when measuring at the second maximum. The unique high power of the ESS proton linac will allow for the measurements to be made at the second maximum and thereby for the most precise measurements of the leptonic CP violation phase δ_CP to be made. This paper describes the results of the work made on the conceptual design of ESSνSB layout, infrastructure, and components as well as the evaluation of the physics performance for leptonic CP violation discovery and, in particular, the precision in the measurement of δ_CP. Full article

In the search for the CP violation (CPV) in the leptonic sector, crucial information was obtained a decade ago from reactor and accelerator experiments. The discovery and measurement of the third neutrino mixing angle, ${\theta }_{13}$, with a value ∼9${}^{\circ }$, allow for the possibility to discover the leptonic Dirac CP-violating angle, ${\delta }_{CP}$, with long baseline neutrino Super Beams. ESS$\nu$SB is a long-baseline neutrino project that will be able to measure the CPV in the leptonic sector at the second oscillation maximum, where the sensitivity of the experiment is higher compared to that at the first oscillation maximum. The extension project, ESS$\nu$SB+, aims to address a very challenging task on measuring the neutrino–nucleon cross-section, which is the dominant term of the systematic uncertainty, in the energy range 0.2–0.6 GeV, using a Low-Energy nuSTORM (LEnuSTORM) and an ENUBET-like Low-Energy Monitored Neutrino Beam (LEMNB) facilities. The target station plays the main role in generating a well defined and focused pion, and hence muon, beam. Full article

The European Spallation Source (ESS) will be the most powerful neutron source in the world. This facility offers a unique opportunity to study fundamental physics, in particular the matter–antimatter asymmetry in the Universe due to the development of a very intense neutrino superbeam. The ESS neutrino Super-Beam project proposes an accelerator complex, complimentary to the existing facility, and an additional target station to produce such a neutrino beam. We give an overview of the ESS$\nu$SB project with details on the accelerator complex, from source to target. We also present the proposed next steps for the ESS$\nu$SB project. Full article

Several anomalies observed in short-baseline neutrino experiments suggest the existence of new light sterile neutrino species. In this review, we describe the potential role of long-baseline experiments in the searches of sterile neutrino properties and, in particular, the new CP-violation phases that appear in the enlarged 3 + 1 scheme. We also assess the impact of light sterile states on the discovery potential of long-baseline experiments of important targets such as the standard 3-flavor CP violation, the neutrino mass hierarchy, and the octant of ${\theta }_{23}$ . Full article