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.

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.

Phys. Part. Nucl. Lett.

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.

Phys. Part. Nucl. Lett.

Simulation of neutrino telescopes like IceCube, Baikal-GVD, KM3NET/ARCA is a long multi-stage process. NTSim is a framework efficiently chaining different stages of the simulation. Full Monte Carlo modeling of electromagnetic and hadron cascades usually consumes a lot of computational resources. In this contribution we present an efficient cascade parametrization of NTSim which allows to significantly reduce computation time and validate it against the full cascade modeling.

JINST

The identification of top quark decays where the top quark has a large momentum transverse to the beam axis, known as $top$$tagging$, is a crucial component in many measurements of Standard Model processes and searches for beyond the Standard Model physics at the Large Hadron Collider. Machine learning techniques have improved the performance of top tagging algorithms, but the size of the systematic uncertainties for all proposed algorithms has not been systematically studied. This paper presents the performance of several machine learning based top tagging algorithms on a dataset constructed from simulated proton-proton collision events measured with the ATLAS detector at $\sqrt{s} = 13$ TeV. The systematic uncertainties associated with these algorithms are estimated through an approximate procedure that is not meant to be used in a physics analysis, but is appropriate for the level of precision required for this study. The most performant algorithms are found to have the largest uncertainties, motivating the development of methods to reduce these uncertainties without compromising performance. To enable such efforts in the wider scientific community, the datasets used in this paper are made publicly available.

JETP Lett.

A phenomenological model of a “running axial mass” (MArun) was previously proposed to calculate cross sections for the quasielastic scattering of neutrinos and antineutrinos on nuclei. It can be easily implemented in neutrino generators and has only two free parameters, which are obtained from the global fit to the experimental data on the total and differential cross sections for the quasielastic scattering of (anti)neutrinos on various nuclear targets. In this work, the NOvA near detector data on the total and differential cross sections for the scattering of muon neutrinos, are compared to the simulation performed using the GENIE neutrino Monte Carlo generator (v.3.4.0), which optionally allows for using the MArun model.

Phys. Atom. Nucl.

The recent results on charmonium production at BESIII are reviewed, including the observation of charmonium-like states in the processes of electron–positron annihilation into $D^{*0}D^{*-}\pi^{+}$, $\omega X(3872)$, $K^{0}_{s}K^{0}_{s}J/\psi$, and $\pi^{+}\pi^{-}\psi_{2}(3823)$ final states, as well as the study of the prompt inclusive production of the $J/\psi$ and $\psi(3686)$ mesons.

Phys.Atom.Nucl.

In November 2020, the IceCube Neutrino Observatory registered a neutrino event with an energy of 150 TeV directed at the Cygnus Cocoon gamma-ray source. In the Carpet-2 experiment, as part of the Baksan Neutrino Observatory (BNO), a sharp increase in the flow of events with an energy above 300 TeV was recorded from the same direction within the angular accuracy of the events. This flux is 4 orders of magnitude higher than the expected intensity of gamma quanta of this energy region according to data in the region of less than 100 TeV. It was expected that such a powerful flare could be registered by the TAIGA-HiSCORE installation of the TAIGA astrophysical complex. We analyzed the events of the EAS recorded by the installation of TAIGA-HiSCORE for 18 h in October–November 2020 from the Cygnus Cocoon source. This article provides the upper limit of the expected excess flow.

Phys. Atom. Nucl.

The existence of dibaryons, the systems with baryon number two, is one of the central questions in modern nuclear physics. It is closely connected with the problem of phase transitions in nuclear matter, various manifestations of which are being searched for in the experiments with colliding heavy nuclei. Since the theory of these processes is very difficult, the interpretation of such data usually contains large uncertainties. At the same time there is a possibility of understanding some features of these processes in the collision of the lightest nuclei–deuterons. Exploring such an opportunity at the future NICA SPD is the focus of this paper. It is shown that while using Kinematical fit technique at the simulation of the process $d+d\rightarrow d+X$ below meson production threshold, the accuracy of the estimation of the $X$ mass is on the level 2–3 MeV/$c$ when the deuteron moment of the NICA Collider is equal to 2.6 GeV/c (below $MX$ is used as a mass of $X$, i.e. $MX=M_{d}+E_{\textrm{exc}}$, where $M_{d}$, $E_{\textrm{exc}}$ are deuteron mass and excitation energy). The system $X$ is called sometimes as dibaryons below.

Phys. Atom. Nucl.

The production of $Z$ bosons in proton–proton collisions and the LHC energies is studied. The production cross sections for $Z$ bosons and their transverse-momentum spectra are calculated along with the lepton angular coefficients as functions of the $Z$-boson transverse momentum. The calculations are performed within the parton Reggeization approach in the leading-order approximation in the strong coupling constant $(Q\bar{Q}\to Z)$ and with allowance for the next-to-leading-order correction associated with Reggeized-quark scattering on a Reggeized gluon $(RQ\to Zq)$. A numerical simulation is performed by means of the KaTie Monte Carlo generator. The results of the calculations are compared with experimental data of the ATLAS Collaboration.