Physics of Particles and Nuclei Letters最新文献

Methods of processing a digital signal obtained from a four-electrode transverse position sensor of ion bunches during acceleration in a synchrotron are discussed. A technique has been developed for reconstructing the amplitude spectrum of betatron oscillations of an ion bunch in the case of a sensor displacement relative to the initial position determined during calibration. The results obtained are used to reconstruct the amplitude spectrum of betatron oscillations of a bunch after injection of xenon ions into the JINR booster synchrotron.

The formation of new nuclei and hypernuclei in heavy-ion collisions at high energies is analysed. We use the hypothesis of local chemical equilibrium in expanding nuclear matter. In this letter, the ultra-relativistic quantum molecular dynamics (UrQMD), the Dubna cascade model (DCM), and statistical multifragmentation model (SMM) are applied for theoretical calculations of nuclei and hypernuclei production. Good agreement with experimental data is obtained within our hybrid approach. Experiments planned for the future at FAIR, NICA, and other accelerators will provide an excellent opportunity for study of nuclei and hot (hyper-)matter.

The first images of the shadows of black holes have opened up new possibilities for testing extended theories of gravity. Using the Newman–Janis method, metrics with rotation for the (R + {{R}^{2}}) model with quantum field corrections are obtained. We have shown that not all previously obtained solutions are consistent with the experimental results of the Event Horizon Telescope. So the more accurate variant to select extended theories of gravity based on black hole rotation taking into account is proposed.

The Highly Granular Neutron Time-of-Flight Detector (HGND) at the BM@N experiment is under development for measuring the energy of neutrons produced in nucleus-nucleus collisions. For the first time, small prototype of the HGND was used in Xe + CsI at 3.0 and 3.8 A GeV run at the BM@N. The online real-time monitoring system recently developed and used for the HGND prototype is discussed.

Abstract

We report the cytotoxic effect of pulse duration and wavelength of UVB laser radiation from Li(Lu,Y)F₄:Ce laser on human skin fibroblasts. When performing the MTT test 24 h after irradiation, an increase in the viability parameter was observed. Flow cytometry showed that 80.8 ± 6.9% of cells have a damaged membrane and only 6.2 ± 2.2% reach the stage of late apoptosis, due to which they have the potential to restore the cytoplasmic membrane and subsequently divide.

The Spin Physics Detector is a collider experiment at NICA designed to study the spin structure of the proton and deuteron and other spin-related phenomena using polarized beams. The collision energy is up to 27 GeV and the luminosity is up to 10³² cm^–2 s^–1 in pp mode. Two scintillator-based detectors, Beam-Beam Counters (BBC), will be installed upstream and downstream the interaction point and will serve as a tool for beam diagnostics including local polarimetry. The BBCs will be designed as high granularity scintillation detectors. In this paper we present the tests of a BBC prototype based on the tiles with the green wavelength shifter and silicon photomultiplier (SiPM) readout. The prototype was tested with 1 × 1 mm² and 3 × 3 mm² SensL SiPM using CAEN FERS-5200 front-end readout system. Amplitude and time response to cosmic rays was compared for different tile configurations.

In this work we simulate the SPD NICA straw tracker detector response in the trigger-less regime using GEANT4 tools. We study the temporal structure of signals and investigate the vertex reconstruction efficiency using the simulation data. We develop a part of prototype software for event reconstruction at the stage of online data filtering.

Abstract

The BM@N 8th run using xenon ion beams was successfully completed in February 2023, resulting in approximately 600 million events. They were recorded in the form of around 31 000 files, with a combined size exceeding 400TB. To process all these data JINR DIRAC platform was chosen. The data reconstruction of BM@N 8th physics run was the first time DIRAC had been used for data reconstruction in JINR. A set of approaches, systems, and methods were developed during this campaign, which aid in reducing the efforts required for future data reconstructions at JINR.

Abstract

The DSpace software platform was specifically designed to create modern open repositories in academic and educational environments. It is an open-source platform with rich functionality, making it an attractive tool for academic, non-profit and commercial organizations creating open digital repositories. DSpace is supported by a large community of developers and users from around the world, allowing researchers and scientists to publish their papers and data. In our work we consider the use of DSpace software for the JINR repository, which contains articles, preprints and other materials reflecting and facilitating to JINR research activities. A test prototype of the repository, the usage of entities and collections, support for English and Russian languages, schemes for obtaining metadata from external resources such as INSPIREHEP, eLIBRARY are presented. The setup of the DSpace platform and its adaptation to the tasks of the JINR institutional repository are also briefly described.

Abstract

This contribution describes improvements to the Baikal-GVD alert system related to alert visualization which could clarify the alert data and its possible relation to astrophysical phenomena. The Baikal-GVD online data processing and alert system was launched at the beginning of 2021. It is designed for fast online neutrino event reconstruction and, when a potential signal from an astrophysical source is detected, sending an alert message to collaboration members. It also searches for coincidences between internal alerts and other astrophysical experiment alerts. The databases schema used to store the alert data (MariaDB, InfluxDB, MongoDB) is described. Automation of data analysis and visualization processes occurs using specialized Python libraries (Matplotlib, Astropy, etc.), which provide an API for that. The capabilities of the Grafana software system for storing visualized data with the ability to share are also explored. One of the main tasks of our alert system is switch to real-time mode with a low latency mode in signal reception both by the Baikal-GVD trigger and in receiving and responding to an external alert.