Physics of Particles and Nuclei Letters最新文献

The K⁺ → π⁰µ⁺νγ(K_µ3γ) and K⁺ → π⁰e⁺νγ (K_e3γ) decays are measured with OKA detector at the RF-separated 17.7 GeV/c momentum kaon beam from the U-70 synchrotron. The data obtained corresponds to the value of 2.62 × 10¹⁰ “live” kaons passing to the decay volume. The ratios of Br(K_µ3γ)/Br(K_µ3) and Br(K_e3γ)/Br(K_e3) are measured. The T-odd correlation ξ_πμγ (ξ_πeγ), which is the mixed product of the momenta of µ⁺(e⁺), π⁰, and γ in the kaon rest frame, is measured. The asymmetry of the distribution in ξ is characterized by the ratio A_ξ = (N₊ − N₋)/(N₊ + N₋), where N₊₍₋₎ is the number of events with positive (negative) ξ. The values of A_ξ for K_µ3γ and for K_e3γ is obtained.

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.

Abstract

This work aims at mathematically simulating the repair process of double-strand DNA breaks induced by rare ionizing radiation. A mathematical simulation of several stages of the cellular response to irradiation has been carried out: (i) Chinese hamster cells of the V79 line in the stationary phase of culture growth to the action of 250 keV X-ray irradiation and (ii) human carcinoma cells in the exponential phase of culture growth to (gamma )-Co(^{{60}}) irradiation. The induction and repair of DNA double-strand breaks and the kinetics of formation of incorrectly repaired DNA double-strand breaks are studied. The simulation data are compared with experimental values.

Abstract

Characteristic identities for (2)- and (3)-split Casimir algebra operators (D(2,1;alpha )) in representations (a{{d}^{{ otimes 2}}}) and (a{{d}^{{ otimes 3}}}) are found; projectors onto the invariant subspaces of these representations are constructed, and formulas for their supertraces are derived. All formulas agree with the universal description of subrepresentations of representations (a{{d}^{{ otimes 2}}}) and (a{{d}^{{ otimes 3}}}) of basic classical Lie superalgebras in terms of Vogel parameters.

Abstract

The contribution of the direct interaction vertex to the (Z to {{l}^{ + }}{{l}^{ - }}gamma ) process is extracted on basis of a measurement of differential distributions over the invariant mass ({{l}^{ pm }}gamma ) at the ATLAS detector. Models of CP-violating effective interaction and CP-preserving effective interaction are considered. The direct vertex can be seen as an effective description of loop corrections within the Standard Model. The contribution of the direct vertex in the CP-preserving model lead to ({text{Br}}left( {Z to {{e}^{ + }}{{e}^{ - }}gamma } right) = left( {3.81 pm 0.53} right) times {{10}^{{ - 5}}},) ({text{Br}}left( {Z to {{mu }^{ + }}{{mu }^{ - }}gamma } right) = left( {3.99 pm 0.47} right) times {{10}^{{ - 5}}}.) Adding an effective model to predictions of the modern PowHeg+PHOTOS and Sherpa 2.2 generators significantly improves the agreement with experimental results. The significance of the additive was 5 and 4.7 standard deviations for PowHeg+PHOTOS and Sherpa 2.2, respectively. The PowHeg+PHOTOS generator with the effective interaction additive describes the experimental data slightly better than other generators with the same type of effective additive.

Abstract

Prussian white is the promising cathode material for rechargeable sodium ion batteries. Here we study phase transitions in commercial Prussian White powder with particle size up to ~10 μm, which was chemically enriched with sodium, and synthesized sodium-enriched Prussian White with particle size of ~1 μm. X-ray diffraction was used to track structural changes during heating up to 250°C. Both powders were found to undergo the transformation of initial rhombohedral phase to dehydrated rhombohedral phase through a formation of cubic phase. Smaller particle size of the synthesized powder leads to more effective dehydration, which decreases temperatures of all phase transitions by ≈10°C compared to commercial Na-enriched Prussian White.

In this overview, recent results of the ALICE collaboration on neutral meson and direct photon production are reported. The invariant cross section of ({{pi }^{0}}) and (eta ) meson production in pp collisions (sqrt s = 13) TeV are measured and compared to pQCD calculations. The direct photon production and two-photons HBT correlations in Pb–Pb (sqrt {{{s}_{{NN}}}} = 5.02) TeV are presented as well.

In order to better understand the dynamics of the quark-hadron phase transition in the presence of a magnetic field, the thermal behaviour of the non-perturbative QCD vacuum has been examined. The dynamical configuration of the resulting dual QCD vacuum and its flux tube configuration have been explored in order to investigate the non-perturbative properties of QCD. Within the context of dual QCD-based hadronic bag, which ensures the critical parameters and the accompanying critical sites for quark-hadron phase transition, related thermodynamic quantities and equation of state (EoS) to define quark matter have also been studied in presence of magnetic field.