JETP Lett.

First results on the polarization of $\Lambda $ hyperons inclusively produced on 26.5-GeV/c${{K}^{ - }}$ and ${{\pi }^{ - }}$ beams are presented. The measurements were carried out using the SPASCHARM setup at the U-70 accelerator facility (Protvino, Russia) on nuclear targets in 2021 and 2022. The polarization of an $\Lambda $ hyperon on the ${{\pi }^{ - }}$ beam does not exceed several percent in most of the studied kinematic region. The data obtained on the ${{K}^{ - }}$-meson beam exhibit a significant positive polarization at large values of the Feynman variable x$_{F}$ and transverse momentum p$_{T}$ measured for the first time on nuclei.

Nucl.Instrum.Meth.A

The calorimeter of the Mu2e experiment is being assembled, with all production components completed and tested, apart from the digital electronics that is still underway. The mechanical structure is fully built, with a complete integration and test of all the analog sensors and electronics. We summarize construction and assembly phases, Quality Control tests, calibration procedures and first tests performed in the assembly area, as well as the installation and commissioning plans of the final disks in the Mu2e hall.

Phys.Part.Nucl.

The review describes the results of experiments based on quite different and independent approaches to solving the problem of interaction of muons with nuclei. Different paths of muon capture by nuclei and subsequent paths of secondary processes are considered: radiationless capture followed by nuclear fission, excitation of the nucleus with the escape of particles (neutrons and charged ones), and excitation of nuclear levels with the escape of gamma quanta. The experimental data require refinement, in particular with respect to the spectroscopy of fission fragments, the spectroscopy of secondary particles, and statistical accuracy. All of the experimental methods described rely on interpretation within theoretical models. Improvement in each of these parts will mutually stimulate refinements or new paths in subsequent research. The article is addressed to young aspiring physicists interested in muon physics and looking for new phenomena of interactions of elementary particles with nuclei and atoms, and solutions to emerging problems using modern experimental methods.

Eur. Phys. J. C

The CMS detector, including its muon system, has been operating at the CERN LHC in increasingly challenging conditions for about 15 years. The muon detector was designed to provide excellent triggering and track reconstruction for muons produced in proton–proton collisons at an instantaneous luminosity ($\mathcal {L}$) of $1 \times 10^{34}$ cm$^{-2}$s$^{-1}$. During the Run 2 data-taking period (2015–2018), the LHC achieved an instantaneous luminosity of twice its design value, resulting in larger background rates and making the efficient detection of muons more difficult. While some backgrounds result from natural radioactivity, cosmic rays, and interactions of the circulating protons with residual gas in the beam pipe, the dominant source of background hits in the muon system arises from proton–proton interactions themselves. Charged hadrons leaving the calorimeters produce energy deposits in the muon chambers. In addition, high-energy particles interacting in the hadron calorimeter and forward shielding elements generate thermal neutrons, which leak out of the calorimeter and shielding structures, filling the CMS cavern. We describe the method used to measure the background rates in the various muon subsystems. These rates, in conjunction with simulations, can be used to estimate the expected backgrounds in the High-Luminosity LHC. This machine will run for at least 10 years starting in 2029 reaching an instantaneous luminosity of $\mathcal {L} = 5 \times \text {10}^\text {34}\,\text {cm}^\text {-2}\,\text {s}^\text {-1}$ and increasing ultimately to $\mathcal {L} = 7.5 \times \text {10}^\text {34}\,\text {cm}^\text {-2}\,\text {s}^\text {-1}$. These background estimates have been a key ingredient for the planning and design of the muon detector upgrade.

AIP Conf. Proc.

An overview of the MONUMENT experimental programme is given, as well as some additional possibilities not yet fully explored in the study of the ordinary muon capture process. The importance of studying partial capture rates, angular correlations in the process, and the hyperfine K-series splitting of mesorengenic radiation is highlighted. The possibility of astrophysical appli-cations is pointed out, given the similarity between the muon capture process and the scattering of intermediate-energy neutrinos from supernova explosions at the nucleus.

Eur. Phys. J. C

The BESIII experiment has been operating since 2009 and has received several upgrades, to study the $\tau $-charm physics utilizing the BEPCII accelerator. The BEPCII is a double-ring multi-bunch collider with a luminosity of $1 \times 10^{33} \, {\text {cm}}^{-2} \, {\text {s}}^{-1}$ optimized at a center-of-mass (cms) energy of $2 \times 1.89$ GeV. The rich physics topics, long lifetime and the large volume of data present challenges to offline data processing. This paper describes the design and implementation of the offline software system to meet the requirements and challenges of BESIII, including offline software architecture, geometry management, database management, event data model and tag-based analysis.

PTEP

We performed a measurement of the inclusive missing-mass spectrum of the |$^{12}$|C|$(K^-, K^+)$| reaction at an incident beam momentum of 1.8 GeV/c. This measurement was carried out by using the Superconducting Kaon Spectrometer (SKS) and the K1.8 beamline spectrometer at the Hadron Experimental Facility in J-PARC. From the missing-mass of the |$^{12}$|C|$(K^-, K^+)$| reaction, the binding energy of a |$\Xi ^-$| hyperon in a core |$^{11}$|B nucleus, |$B_{\Xi ^-}$|⁠, can be calculated. Our experimental setup yielded a good energy resolution of 8.2 MeV (full width at half maximum), which allowed us to observe significant enhancements in the proximity of the |$^{12}_{\Xi }$|Be production threshold region. In order to extract information from the missing-mass spectrum, we employed several fitting parameters assumptions. A good agreement with the spectrum shape was obtained by adding two Gaussian functions, with the constant experimental resolution for the |$\Xi$|-hypernuclear states, to the background distribution. The peak positions were obtained to be |$B_{\Xi ^-} = 8.9 \pm 1.4$| (stat.) |$^{+3.8}_{-3.1}$| (syst.) MeV and |$B_{\Xi ^-} = -2.4 \pm 1.3$| (stat.) |$^{+2.8}_{-1.2}$| (syst.) MeV. Another model assumption, one Breit–Wigner function with |$B_{\Xi ^-} = -2.7 \pm 2.2$| (stat.) |$^{+0.5}_{-0.7}$| (syst.) MeV and |$\Gamma = 4.1 \pm 2.1$| (stat.) |$^{+1.2}_{-0.7}$| (syst.) MeV, also yielded a similar |$\chi ^2$| value.

Universe

Ground-based observations of Very High Energy (VHE) gamma rays from extreme astrophysical sources are significantly influenced by atmospheric conditions. This is due to the atmosphere being an integral part of the detector when utilizing Imaging Atmospheric Cherenkov Telescopes (IACTs). Clouds and dust particles diminish atmospheric transmission of Cherenkov light, thereby impacting the reconstruction of the air showers and consequently the reconstructed gamma-ray spectra. Precise measurements of atmospheric transmission above Cherenkov observatories play a pivotal role in the accuracy of the analysed data, among which the corrections of the reconstructed energies and fluxes of incoming gamma rays, and in establishing observation strategies for different types of gamma-ray emitting sources. The Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescopes and the Cherenkov Telescope Array Observatory (CTAO), both located on the Observatorio del Roque de los Muchachos (ORM), La Palma, Canary Islands, use different sets of auxiliary instruments for real-time characterisation of the atmosphere. In this paper, historical data taken by MAGIC LIDAR (LIght Detection And Ranging) and CTAO FRAM (F/Photometric Robotic Telescope) are presented. From the atmospheric aerosol transmission profiles measured by the MAGIC LIDAR and CTAO FRAM aerosol optical depth maps, we obtain the characterisation of the clouds above the ORM at La Palma needed for data correction and optimal observation scheduling.

Phys.Atom.Nucl.

The production of polarized $J/\psi$ mesons at the NICA (Nuclotron based Ion Collider fAcility) energy of $\sqrt{s}=27$ GeV is studied on the basis of the generalized parton model in the leading order of perturbative QCD. The hadronization of a $c\bar{c}$ quark pair to a $J/\psi$ meson is described within the model of nonrelativistic QCD. Nonperturbative model parameters are determined on the basis of a comparison with available experimental data on the production of prompt $J/\psi$ mesons at the energies of $\sqrt{s}=19.4$ GeV (NA3) and $\sqrt{s}=200$ GeV (PHENIX).

Bull.Russ.Acad.Sci.Phys.

Spectra of deuterons and tritons are measured upon the absorption of stopped π$^{−}$ mesons on a live target (an analog of a $^{28}$Si target). It is shown this technique allows the identification of direct pathways for the formation of deuterons and tritons. The share of these particles in the total yields is ~30%.

Phys.Part.Nucl.

MPDRoot is an off-line software framework for simulation, reconstruction, and physical analysis of the simulated or experimental data for MPD experiment at NICA collider. The experiment is projected to run for a few decades and to obtain ~10$^{8}$ events of heavy ion collisions, collecting the data for physics analysis at the 100 PB scale. For overall experiment success it is imperative to have state of the art data analysis software, which integrates best of available latest technologies, while adhering to time-proven, most effective development methodologies. In this paper, we introduce the MPD Data Lab—the technological integration of Acceptance Test Driven Development and Rapid Development concepts into the MPDRoot framework. At the beginning, we standardized the existing codebase by designing and writing API. This was a necessary step to be able to plug-in the external diagnostic software entities and to make the in-depth comparison of different realizations of the reconstruction modules possible. The logic of the diagnostics is encapsulated into the separate controller—the QA Engine, while its visualization is provided by JupyterLab framework. We show how full integration of MPDRoot’s libraries into JupyterLab enables to use the power of rapid development provided by JupyterLab technology to enhance productivity by fast prototyping of MPDRoot’s algorithms. The combination of these technologies together with the existing development environment form a software complex, providing means to accomplish the long term strategic objectives—competent software development with reliable quality control and algorithm innovation.

Phys. Part. Nucl.

We report on newest results in ${{k}_{{\text{T}}}}$-factorization approach for $ep$-processes. We describe HERA data on longitudinal structure function measurements as well as on associated prompt photon and jet photoproduction. The calculations include first application of the new LLM-2022 transverse momentum dependent gluon distribution developed by the authors. The study includes also the first implementation of parton showers for photoproduction processes in ${{k}_{{\text{T}}}}$-factorization. The data are described well with the simulations. The $ep$-processes are included to the new version of Monte-Carlo generator pegasus.

Phys.Part.Nucl.

A review on the gluon transverse momentum dependent distribution (TMD) and its application to the analysis of the $ep$ DIS at the HERA energies, hard and soft $pp$ processes at LHC energies and mid-rapidity is presented.

Phys.Part.Nucl.

Further development of the approach to the study of relativistic nuclear interactions in the space of four-dimensional velocities using the similarity principle is reported. In essence, the approach is modified by including quark–gluon dynamics in hadron generation during nucleus–nucleus interactions in the central rapidity region. Inclusive spectra of pions and kaons produced in pp and nucleus–nucleus, collisions are studied as a function of their transverse momentum p$_{T}$ in the central rapidity region calculated within the modified approach based on the assumption of similarity of inclusive hadron spectra. A satisfactory description is given of the NA61/SHINE data for the yield ratios K$^{+}$/π$^{+}$ and K$^{−}$/π$^{−}$ as a function of $\sqrt s $ in pp and BeBe collisions. Calculations of antiparticle-to-particle yield ratios (${{\bar {p}} \mathord{\left/ {\vphantom {{\bar {p}} p}} \right. \kern-0em} p}$, ${{\bar {d}} \mathord{\left/ {\vphantom {{\bar {d}} d}} \right. \kern-0em} d}$, ${{{{{\overline {{\text{He}}} }}^{3}}} \mathord{\left/ {\vphantom {{{{{\overline {{\text{He}}} }}^{3}}} {{\text{H}}{{{\text{e}}}^{3}}}}} \right. \kern-0em} {{\text{H}}{{{\text{e}}}^{3}}}}$) in proton–proton and nucleus–nucleus reactions are presented.

Nucl.Instrum.Meth.A

The Mu2e experiment at Fermilab will search for the neutrino-less coherent conversion of a muon into an electron in the field of a nucleus. Mu2e detectors comprise a straw tracker, an electromagnetic calorimeter and a veto for cosmic rays. The calorimeter employs 1348 Cesium Iodide crystals readout by silicon photo-multipliers and fast front-end, and digitization electronics. The digitization board is named DiRAC (Digitizer ReAdout Controller) and 140 cards are needed for the readout of the full calorimeter. The DiRACs are hosted in crates located on the external surface of calorimeter disks, inside the detector solenoid cryostat and must sustain very high radiation and magnetic field so it was necessary to fully qualify it. Several version of prototypes were validated for operation in a high-vacuum (10⁻⁴ Torr) and under a 1T magnetic field. An extensive radiation hardness qualification campaign, carried out with photons, 14 MeV neutron beams, and 200 MeV protons, certified the DiRAC design to sustain doses up to 12 krad, neutron fluences up to $\sim 10^{11}1{\mathrm{MeV\; n}}_{eq}/{\mathrm{cm}}^2$, and very low occurrences of single-event effects. The qualification campaigns and quality assurance procedures will be reviewed.

Phys.Part.Nucl.Lett.

This paper describes the results of applying an evolutionary algorithm to optimize the hyperparameters of a neural network (NN) solving the problem of separating the rare Higgs boson birth process in association with a single top quark $pp \to tH(H \to bb)$ from the main background processes $pp \to tt,ttH,tZbq$.

Phys.Part.Nucl.Lett.

The $\nu $GeN experiment aims to search for coherent elastic neutrino-nucleus scattering and to study the other rare processes. The experimental setup is located about 12 m from the center of the 3.1 GWth reactor no. 3 of Kalinin NPP providing the antineutrino flux of (3.6–4.4) × 10$^{{13}}$ particles cm$^{–2}$ s$^{–1}$. The intense antineutrino flux gives a possibility to detect coherent elastic scattering of reactor antineutrinos on Ge nuclei in the regime of full coherence, as well as to study other properties of neutrinos.

Adv.Space Res.

The main goal of the TUS experiment was to search for and study ultra high-energy cosmic rays with energies E > 70 EeV. At the same time, the TUS detector registered a number of unusual events, the origin of which was unclear. Events that are unique and not similar to EAS are the subject of the study presented in this paper. Events such as gamma-ray bursts (GRBs), out-of-aperture upward going EASs accompanied by lightning flashes, as well as terrestrial gamma-ray flashes (TGFs) are considered as their possible sources.

Phys.Part.Nucl.Lett.

JINR is developing а novate cyclotron for proton therapy (including FLASH) for new JINR’s international biomedical research center. The project is about to be put into manufacturing stage. As unavoidable parts of this process, engineering, mechanical, and production limitations impose correction on the physical conceptual design of the cyclotron. Therefore, the initial extraction system, consisting of an electrostatic deflector followed by two magnetic channels with their compensators, was adjusted accordingly to the new model and improved for upcoming manufacturing stage.

Phys.Part.Nucl.Lett.

Modern astronomy aims to study the astrophysical objects with the various types of signals incoming from them. To achieve the goals of the multi-messenger astronomy, experiments should exchange data, that can be done with the alert messages. Alert contains essential information about the detected event. These messages are distributed via international networks facilitating the rapid follow-up of transient astrophysical phenomena. The Baikal-GVD alert system receives external alerts and applies different methods to search for signal coincidences. For better understanding of the alert system workflow and researching of the astrophysical neutrino sources the alert visualization is necessary. This work deals with the techniques that are used within the coincidence search process and the visualization of the alerts: Baikal-GVD alerts and external messages from experiments like the IceCube neutrino telescope, Fermi gamma-ray telescope and LIGO/Virgo/KAGRA gravitational observatories.

Phys. Part. Nucl. Lett.

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.

Phys.Part.Nucl.Lett.

The NOvA experiment, aimed at studying the neutrino oscillations in the muon neutrino and antineutrinos beam, uses two segmented liquid scintillator detectors, with masses of 300 tons and 14 kilotons, respectively. The large size and high segmentation of the NOvA detectors, as well as a flexible system of software triggers and data acquisition, make it possible to solve additional physical problems, in particular, to detect and study the atmospheric neutrino flux. This paper presents simulating events from interactions of the atmospheric neutrinos in the far detector of the NOvA experiment, as well as a preliminary evaluation of the efficiency of signal event selection.

Phys.Part.Nucl.Lett.

DUNE is a long-baseline experiment for neutrino oscillation studies. Its near detector complex consists of three main parts. One of them is ND-LAr, the liquid argon time projection chamber (LAr-TPC). In LAr-TPC’s, a light collecting system (LCS) is commonly used as a trigger system. In this work the ND-LAr LCS is considered. The data from ProtoDUNE Dual Phase and Module 0 LAr-TPC prototypes was used to obtain the parameters of scintillation in liquid argon for Geant4 simulation. Then, the response of the Module 0 LCS in events with cosmic muons was compared with the response of its Geant4 model in identical simulated events to estimate the photon detection efficiency of the ND-LAr LCS. After that, single-particle and two-particle events with different shifts in time and space between tracks were simulated to determine the time and spatial resolution of the ND-LAr LCS. Obtained results allow us to judge whether the characteristics of the ND-LAr LCS satisfy the experiment requirements.

Phys.Part.Nucl.Lett.

The custom Application Specific Integrated Circuits (ASIC) Turin Integrated Gem Electronics for Readout (TIGER) has been developed at INFN-Torino and is capable of simultaneous precise measurements of both the charge and time characteristics of signals in micropattern gaseous detectors. Its flexibility makes it attractive as a front-end electronics solution for a wide range of applications, including readout systems of Straw Trackers in future High Energy and Neutrino Physics experiments. We present first performance measurements done with straw drift tubes operated with TIGER readout. Preliminary results obtained with the SPS muon beam at CERN are compared to the prediction of simulation studies done with GARFIEDL++ and LTSpice packages.

Phys.Part.Nucl.Lett.

In this paper we study the signal-to-background ratios for the $J{\text{/}}\psi $-meson associated and direct photon main production processes at the energies of SPD NICA experiment using the Monte Carlo generator PYTHIA8. We extract the set of kinematic constraints allowing to improve signal-to-background ratios. We compare the results of our simulation for the direct photon spectra in different intervals of ${{p}_{T}}$ and ${{x}_{F}}$ with the experimental data and present the predictions for signal-to-background ratios in direct photon production at the NICA energy of $\sqrt s = 27$ GeV.