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Concept of Coherence in Neutrino and Antineutrino Scattering off Nuclei
No full textThe concept of coherence in the scattering of neutrinos and antineutrinos off nuclei is discussed. Motivated by the results of the COHERENT experiment, a new approach to coherence in these processes is proposed, which allows a unified description of the elastic (coherent) and inelastic (incoherent) contributions to the total cross section for neutrino and antineutrino scattering off nuclei at energies below 100 MeV. Experiments and physical problems for coherent scattering of (anti)neutrinos off nuclei are briefly discussed. The extended appendix covers the main points and conclusions of the proposed approach in pedagogical detail
First Results from Operating a Prototype Wide-Angle Telescope for the TAIGA Installation
No full textThe prototype of a small wide-angle telescope was installed within the astrophysical complex TAIGA in the Tunka Valley in September 2019. Data were collected on the prototype’s performance during the last eight observation sessions. Operating regimes of the telescope’s systems, the trigger system, and the system for synchronizing with the TAIGA complex were tested. The first results from analyzing data on the prototype telescope’s performance are presented
Instantons with Quantum Core
No full textWe consider new instantons that appear as a result of accounting for quantum fluctuations. These fluctuations naturally regularize the O(4) singular solutions abandoned in Coleman's theory. In the previous works [3,4] we showed how new instantons modify the widely accepted picture of false vacuum decay in two particular examples of exactly solvable potentials. Here we generalize our consideration to arbitrary potentials and provide a general theory of these new instantons with quantum cores in which vacuum fluctuations dominate. We develop a method that allows us to determine the parameters of instantons for generic potentials not only in the thin-wall approximation but also in the cases where this approximation fails. Unlike the Coleman instantons, the instantons with quantum cores always exist in the cases where the vacuum must be unstable
Establishment of a Modern Experimental Technique of a p Scattering Experiment at J-PARC
No full textA part of the experiment was performed in 2018 and 2019 in J-PARC. As a result of analyzing the collected data, the \Sigma ^{ - }Σ − production and the \Sigma ^{ - }pΣ − p scattering reaction have been identified. It means that our new measurement and analysis method are successfully working well. Analysis for deriving the differential cross section of the \Sigma pΣp scattering is on going
Depth of the Maximum of Extensive Air Showers (EASes) and the Mean Mass Composition of Primary Cosmic Rays in the 10–10 eV Range of Energies, According to Data from the TUNKA-133 and TAIGA-HiSCORE Arrays for Detecting EAS Cherenkov Light in the Tunkinsk Valley
No full textA corrected energy dependence of the depth of the maximum in the wide range of energies 10 to 10 eV is obtained using data collected at the Tunka-133 facility over 7 years of operation (2009–2017) and the TAIGA-HiSCORE facility in the 2019–2020 season. At the highest energies, our results match those of the Pierre Auger observatory. The results are converted to parameter ❬ln A❭, which characterizes the mean EAS composition
A Vector Finder Toolkit for Track Reconstruction in MPD ITS
No full textAs a part of the future upgrade program of the Multi-Purpose Detector (MPD) experiment at the Nuclotron-Based Ion Collider Facility (NICA) complex, an Inner Tracking System (ITS) made of Monolitic Active Pixel Sensors (MAPSs) is proposed between the beam pipe and the Time Projection Chamber (TPC). It is expected that the new detector will enhance the experimental potential for the reconstruction of short-lived particles—in particular, those containing the open charm particle. To study the detector performance and select its best configuration, a track reconstruction approach based on a constrained combinatorial search was developed and implemented as a software toolkit called Vector Finder. This paper describes the proposed approach and demonstrates its characteristics for primary and secondary track finding in ITS, ITS-to-TPC track matching and hyperon reconstruction within the MPD software framework. The results were obtained on a set of simulated central gold–gold collision events at sNN=9 GeV with an average multiplicity of ∼1000 charged particles in the detector acceptance produced with the Ultra-Relativistic Quantum Molecular Dynamics (UrQMD) generator