Physics of Particles and Nuclei Letters最新文献

Baikal-GVD is a cubic kilometer-scale neutrino detector currently under construction in Lake Baikal, Russia. The detector has been taking scientific data in partial configurations since 2016 and is now 70% complete. We present a search for astrophysical point-like neutrino sources using a 5-year track-like event dataset collected by Baikal-GVD in 2019–2024 yr. No significant neutrino source has been found in this analysis. Therefore we compute upper limits for a selection of candidate objects. The results are compared to published results from IceCube, ANTARES and KM3NeT.

Active work continues on the creation of the SPD (Spin Physics Detector) facility at the NICA accelerator complex, which is located at the Joint Institute for Nuclear Research. Since the detector or facility will collect a large amount of data, data processing and storage will be carried out in a distributed computing environment. Despite the fact that the detector will not be launched soon, active work is already underway on the infrastructure in which the accumulated data will be stored and processed. The data management system Rucio, a standard solution for data management in the field of high energy physics, is used as a management tool. The system has already been launched, integrated into an offline data processing system, and manages terabytes of data. There are also already active users. And there is a need to monitor the state of the system, its operability, as well as user activity. The report presents the experience of designing a monitoring system for the Rucio data management system.

The transverse momentum spectra of charged hadrons reflect the kinetic freeze-out conditions in nuclear collisions. Analysis of these spectra enables quantitative extraction of the system’s thermodynamic parameters. The anisotropic flows probe the system’s collective behavior and its evolution from initial spatial anisotropy to final momentum-space correlations. In this work, the ultra-relativistic quantum molecular Dynamics (UrQMD) model is employed to investigate transverse momentum (({{p}_{{text{T}}}})) spectra and anisotropic flow coefficients (({{v}_{n}})) of charged hadrons in O + O, Kr + Kr, and Xe + Xe collisions at (sqrt {{{s}_{{NN}}}} = 6) GeV, addressing the physics program of the upcoming SPD experiment at NICA. The kinetic freeze-out temperature and radial flow velocity are extracted from these spectra using blast-wave parameterization. The elliptic (({{v}_{2}})) and triangular (({{v}_{3}})) flows are presented as functions of the collision centrality. A systematic comparison of thermal and collective properties across different colliding systems is performed. The obtained results will contribute to understanding strongly interacting matter in the NICA energy regime.

Methodology for developing the data management system (DMS) for BM@N, a fixed target experiment at the NICA (Nuclotron-based Ion Collider fAcility) project is presented. The data management system provides all the necessary tools for secure and efficient data transfer, file cataloging and replication of the experiment data. The goals of implementation of the DMS logging and monitoring services, integrity and consistency checks, user interfaces and authorization are described. One of the key points in the development methodology is focused on providing universal access to file replicas, as well as implementation of a file (or dataset) metadata service for the efficient search of data required for a specific processing or physics analysis.

A time-domain transition method for fully analytical approximations of gravitational waveforms generated by neutron star-black hole mergers is proposed.

A 3D numerical model of an inductive oven for the DECRIS‑PM ECR ion source (FLNR JINR) has been developed to enable high‑intensity metal ion beams for superheavy element research (Z  = 119, 120). Through coupled electromagnetic and thermal simulations, an optimized “cut plug” geometry was identified that enhances the heating efficiency by up to 33 %. The design satisfies magnetic safety requirements and is compatible with the existing source layout, providing a safe solution for the future metal ion beam experiments.

The associated production of a Higgs boson with a single top quark provides direct sensitivity to the relative phase and magnitude of the Higgs–top coupling. Due to the high similarity of the final–state signature with the dominant backgrounds and extremely small number of signal events, machine learning techniques are required to achieve sufficient signal–background separation. Results of Deep Neural Network (DNN) approaches as a cross-check method for event classification problem in the ATLAS analysis are presented in this paper.

Cryogenic technology has been constantly developing due to the advent of relatively inexpensive and high-quality superconducting cables, including those of domestic production. Thermometry system based on cryogenic temperature sensors and special measurement electronic modules is an important element for ensuring and monitoring the operation of cryogenic devices and complexes. The article describes the development of the precision electronics module PKT-4SD, which is basis of thermometry system of the electron-string ion source (ESIS) KRION-6T. ESIS KRION-6T is one of the main part of Laboratory of High Energy Physics NICA injector in the Joint Institute for Nuclear Research.

This work presents a reconstruction of the (_{Lambda }^{3}{text{H}}) hypernucleus in its two-body mesonic decay channel, featuring improved selection criteria to suppress background contributions. A comparison of two versions of the BmnRoot analysis framework shows a substantial increase in reconstruction efficiency after improvements to the tracking algorithms. A qualitative assessment of geometric decay parameters is also carried out, comparing model predictions with experimental data.

The space charge of intense non-relativistic ion beam affects its dynamics. For the longitudinal degree of freedom, the space charge force distorts the RF potential well and, consequently, affects the longitudinal beam density. In equilibrium the beam phase space density is set by balance between electron cooling force and beam heating due to intrabeam scattering. The shape of separatrix and phase space trajectories for such beam are modified by its self-field, which needs to be accounted in computation of the beam longitudinal density and momentum spread. In this paper, we consider usage of Haissinski equation for finding equilibrium momentum spread of bunched ion beam in application to Booster synchrotron of NICA accelerator complex.