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.

Instrum. Exp. Tech.

The paper is devoted to the modeling and analysis of data detected by the TAIGA-IACT installation in the stereo mode. Five Imaging Atmospheric Cherenkov Telescopes (IACT) with a viewing angle of 9.6° are expected to be included in the installation. Today there are three telescopes spaced far apart (from 320 to 500 m) in the installation. The effective area of the installation is as large as 0.6 km$^{2}$; therefore, it is possible to conduct statistically significant measurements of weak γ-ray sources in the energy range above 10 TeV over a reasonable observation time (300–400 h). The Monte Carlo procedure for simulating the hadrons and γ-rays detected by the telescopes is described as is the procedure for reconstructing the parameters of extensive air showers, such as the arrival direction of an event, the axis position, the depth of the maximum of shower development (X$_{max}$), and the primary-particle energy. In order to solve the problem of γ-hadron separation, the criteria for selecting γ-rays detected in the stereo mode have been optimized and the effective area of the installation has been calculated.

Instrum. Exp. Tech.

The first results from the development of previously unknown tellurium-loaded plastic scintillators based on polystyrene, poly(methyl methacrylate), and their copolymers for detectors for the search and study of neutrinoless double beta decay are reported herein. A complex compound of diphenyltellurium oxide with di-(2-ethylhexyl)phosphoric acid and diphenyltellurium di-2-ethylhexanoate were used as tellurium-containing additives. The conditions for obtaining samples have been described and their light yield and transparency has been characterized.

Phys. Part. Nucl.

The SPD (Spin Physics Detector) detector, being built at the NICA collider at JINR, will produce trillions of physics events per year, estimated at dozens of petabytes of data, which puts it on a par with experiments at the Large Hadron Collider. Although the physics facility is under construction, these figures must be taken into account now, at the design stage of an offline data storage and processing system. The needs of physics groups in computing power for carrying out such calculations are constantly growing and already occupy a fairly significant amount of processor time on the computing resources of JINR. The status of work on building a system for managing SPD experiment data storage and processing is presented in this article.

Phys.Part.Nucl.

The EventIndex is the complete catalogue of all ATLAS real and simulated events, keeping the references to all permanent files that contain a given event in any processing stage; its implementation has been substantially revised in advance of LHC Run 3 to be able to scale to the higher production rates. The Event Picking Server automates the procedure of finding the locations of large numbers of events, extracting and collecting them into separate files. It supports different formats of events and has an elastic workflow for different input data. The convenient graphical interface of the Event Picking Server is integrated with ATLAS SSO. The monitoring system controls the performance of all parts of the service.

Phys.Part.Nucl.

The SPD experiment has to collect large amount of data: up to trillion events (records of a collision results) have to be stored and analyzed, producing tens of petabytes of data. This information will be distributed between a number of computing sites on a various storage locations, with duplication to avoid data loss and improve performance. An information system is necessary to efficiently access all instances of the events, and the SPD Event Index is being developed for this purpose. It is a catalog of all events obtained from the detector or simulated, in all permanent instances of different formats and versions.

10.23730/CYRSP-2024-001.105

If you query the arXiv electronic database of preprints and look at the topics of published articles, you can see that roughly one in five deals with hadron spectroscopy. During its development, this area of particle physics has experienced several rises and falls. Today, it is a rapidly developing branch of science, which comprises a significant part of the research program of almost every accelerator experiment. It is especially valid for B-, cτ -factories and, certainly, the LHC, where exciting results have been obtained. The purpose of this lecture is to try giving an overview of the current state of hadron spectroscopy through the eyes of an experimentalist.

Phys.Rev.D

Borexino could efficiently distinguish between $\alpha$ and $\beta$ radiation in its liquid scintillator by the characteristic time profile of its scintillation pulse. This $\alpha /\beta$ discrimination, first demonstrated on the ton scale in the counting test facility prototype, was used throughout the lifetime of the experiment between 2007 and 2021. With this method, the $\alpha$ events are identified and subtracted from the solar neutrino events similar to $\beta$. This is particularly important in liquid scintillators, as the $\alpha$ scintillation is strongly quenched. In Borexino, the prominent ${}^{210}\mathrm{Po}$ decay peak was a background in the energy range of electrons scattered from ${}^7\mathrm{Be}$ solar neutrinos. Optimal $\alpha /\beta$ discrimination was achieved with a multilayer perceptron neural network, with a higher ability to leverage the timing information of the scintillation photons detected by the photomultiplier tubes. An event-by-event, high efficiency, stable, and uniform pulse shape discrimination was essential in characterizing the spatial distribution of background in the detector. This benefited most Borexino measurements, including solar neutrinos in the $pp$ chain and the first direct observation of the CNO cycle in the Sun. This paper presents key milestones in $\alpha /\beta$ discrimination in Borexino as a term of comparison for current and future large liquid scintillator detectors.

Phys.Rev.D

We present the first search for the leptonic decays $D^{*+}\to e^+\nu_e$ and $D^{*+}\to \mu^+\nu_\mu$ by analyzing a data sample of electron-positron collisions recorded with the BESIII detector at center-of-mass energies between 4.178 and 4.226 GeV, corresponding to an integrated luminosity of 6.32~fb$^{-1}$. No significant signal is observed. The upper limits on the branching fractions for $D^{*+}\to e^+\nu_e$ and $D^{*+}\to \mu^+\nu_\mu$ are set to be $1.1 \times 10^{-5}$ and $4.3 \times 10^{-6}$ at 90% confidence level, respectively.

EPJ Web Conf.

The ATLAS Eventlndex is the global catalogue of all ATLAS real and simulated events. During the LHC long shutdown between Run 2 (20152018) and Run 3 (2022-2025) all its components were substantially revised and a new system was deployed for the start of Run 3 in Spring 2022. The new core storage system, based on HBase tables with a SQL interface provided by Phoenix, allows much faster data ingestion rates and scales much better than the old one to the data rates expected for the end of Run 3 and beyond. All user interfaces were also revised and a new command-line interface and web services were also deployed. The new system was initially populated with all existing data relative to Run 1 and Run 2 datasets, and then put online to receive Run 3 data in real time. After extensive testing, the old system, which ran in parallel to the new one for a few months, was finally switched off in October 2022. This paper describes the new system, the move of all existing data from the old to the new storage schemas and the operational experience gathered so far.

JINST

Inelastic beam-gas collisions at the Large Hadron Collider (LHC), within a few hundred metres of the ATLAS experiment, are known to give the dominant contribution to beam backgrounds. These are monitored by ATLAS with a dedicated Beam Conditions Monitor (BCM) and with the rate of fake jets in the calorimeters. These two methods are complementary since the BCM probes backgrounds just around the beam pipe while fake jets are observed at radii of up to several metres. In order to quantify the correlation between the residual gas density in the LHC beam vacuum and the experimental backgrounds recorded by ATLAS, several dedicated tests were performed during LHC Run 2. Local pressure bumps, with a gas density several orders of magnitude higher than during normal operation, were introduced at different locations. The changes of beam-related backgrounds, seen in ATLAS, are correlated with the local pressure variation. In addition the rates of beam-gas events are estimated from the pressure measurements and pressure bump profiles obtained from calculations. Using these rates, the efficiency of the ATLAS beam background monitors to detect beam-gas events is derived as a function of distance from the interaction point. These efficiencies and characteristic distributions of fake jets from the beam backgrounds are found to be in good agreement with results of beam-gas simulations performed with the FLUKA Monte Carlo programme.

Nucl. Instrum. Meth. A

In view of the High Luminosity upgrade of the CERN LHC, the forward CMS Muon spectrometer will be extended with two new stations of improved Resistive Plate Chambers (iRPC) covering the pseudorapidity range from 1.8 to 2.4. Compared to the present RPC system, the gap thickness is reduced to lower the avalanche charge, and an innovative 2D strip readout geometry is proposed. These improvements will allow iRPC detector to cope with higher background rates. A new Front-End-Board (FEB) is designed to readout iRPC signals with a threshold as low as 30fC and an integrated Time Digital Converter with a resolution of 30ps. In addition, the communication bandwidth is significantly increased by using optical fibers. The history, final design, certification, and calibration of this FEB are presented.

Phys. Rev. D

Using data samples with an integrated luminosity of $4.5~\text{fb}^{-1}$ collected by the BESIII detector at center-of-mass energies ranging from 4.66 to 4.95 GeV, we study the processes of $e^+e^-\to\omega X(3872)$ and $e^+e^-\to\gamma X(3872)$. With the $e^+e^-\to\omega X(3872)$ process, the branching fraction ratio $R\equiv\frac{\mathcal{B}(X(3872)\to\gamma J/\psi)}{\mathcal{B}(X(3872)\to\pi^+\pi^- J/\psi)}$ is measured to be $0.38\pm0.20_\text{stat.}\pm0.01_\text{syst.}$ ($R< 0.83$ at 90% confidence level). In addition, we measure the ratio of the average cross section of $e^+e^-\to\omega X(3872)$ to $e^+e^-\to\omega \chi_{c1}(\omega\chi_{c2})$ to be $\sigma_{\omega X(3872)}/\sigma_{\omega\chi_{c1}}~(\sigma_{\omega X(3872)}/\sigma_{\omega\chi_{c2}})=5.2\pm1.0_\text{stat.}\pm1.9_\text{syst.}~ (5.5\pm1.1_\text{stat.}\pm2.4_\text{syst.})$. Finally, we search for the process of $e^+e^-\to\gamma X(3872)$, and no obvious signal is observed. The upper limit on the ratio of the average cross section of $e^+e^-\to\gamma X(3872)$ to $e^+e^-\to\omega X(3872)$ is set as $\sigma_{\gamma X(3872)}/\sigma_{\omega X(3872)}<0.23$ at 90% confidence level.

Phys. Rev. D

Using $e^+e^-$ collision data, corresponding to an integrated luminosity of $892\,\rm pb^{-1}$ collected at center-of-mass energies from 4.84 to 4.95 GeV with the BESIII detector, we search for the process $e^+e^-\to K^+ K^- \psi(3770)$ by reconstructing two charged kaons and one $D$ meson from $\psi(3770)$. No significant signal of $e^+e^-\to K^+ K^- \psi(3770)$ is found and the upper limits of the Born cross sections are reported at 90% confidence level.

JETP Lett.

We update the phenomenological parameters of the Transverse Momentum Dependent (TMD, or unintegrated) gluon density in a proton proposed in our previous studies. This analysis is based on the analytical expression for starting gluon distribution which provides a self-consistent simultaneous description of HERA data on proton structure function $F_2(x,Q^2)$, reduced cross section for the electron-proton deep inelastic scattering at low $Q^2$ and soft hadron production in $pp$ collisions at the LHC conditions. We extend it to the whole kinematical region using the Catani-Ciafaloni-Fiorani-Marchesini (CCFM) evolution equation. Exploiting our previous results on a number of semihard QCD processes, we performed a combined fit to an extended set of LHC and HERA data, comprising a total of $509$ points from $16$ data sets. We illustrate our fit by applying the derived TMD gluon density in a proton to inclusive prompt photon photoproduction at HERA.

JHEP

The Born cross sections for the process $e^{+}e^{-}\to \omega\eta^{\prime}$ are measured at 22 center-of-mass energies from 2.000 to 3.080 GeV using data collected with the BESIII detector at the BEPCII collider. A resonant structure is observed with a statistical significance of 9.6$\sigma$. A Breit-Wigner fit determines its mass to be $M_R=(2153\pm30\pm31)~{\rm{MeV}}/c^{2}$ and its width to be $\Gamma_{R}=(167\pm77\pm7)~\rm{MeV}$, where the first uncertainties are statistical and the second are systematic.

JETP Lett.

Nuclear deep inelastic structure functions F_2^A(x,Q^2) as well as parton distribution functions in a nuclei are investigated in the framework of rescaling model. Our analysis is based on analytical expressions for quark and gluon densities in a proton derived at the leading order of QCD coupling. By fitting the rescaling parameters from the experimental data on F_2^A(x,Q^2)/F_2^D(x,Q^2) ratio for several nuclear targets, we derive predictions for corresponding nuclear parton distributions and, thus, for shadowing and antishadowing effects.

Phys.Part.Nucl.Lett.

A technique for producing, adjusting, and testing large-area scintillation detectors (≥1 m$^{2}$) for active cosmic muon shielding in low-background experiments is presented. The detectors developed feature a high efficiency (~99.75%) and low light collection inhomogeneity (≤25%); they can be used to construct modular systems for active muon shielding with different coverage areas and the interchangeability of modules. The testing method applied makes it possible to significantly reduce the time of checking light collection inhomogeneity of scintillation panels

Phys.Part.Nucl.

The review is concerned with studies of one-nucleon and two-nucleon halos in isobar analog states of light nuclei with $A = 6,\,\,12,\,\,13,\,\,14$. The study allow us to investigate manifestations of isotopic invariance in new objects and to relate properties of the neutrino and proton halos. The existence of a halo in isobar analog states has been little studied experimentally so far. It is proposed to solve the problem of experimentally determining the radii of some possible halo states in nuclei from $^{6}$Li to $^{14}$O that make up isobar analog doublets and triplets. New possible halo candidates are found in the $^{13}$C and $^{13}$N mirror nuclei, in the $A$ = 12 and $A$ = 14 isobar analog multiplets. Note that the isobar analog states with $T = 1$ in the $A = 12$ triplet are experimentally investigated for the first time in the transfer and charge-exchange reactions. It is established that the root-mean-square radii of the ${{0}^{ + }}$ states in the $A = 6$ multiplet coincide within errors. The results are obtained by two independent methods, ANC and MDM.

Phys.Part.Nucl.

The main features and characteristics of the ${{k}_{{\text{T}}}}$-factorization QCD approach, which is based on BFKL-like noncollinear gluon evolution equations, are outlined. One of the advantages of this approach is connected with a convenience of including a significant part of higher order perturbative QCD corrections. The explicit expression and solutions of some parton distribution evolution equations in the leading logarithmic approximation are presented. Frequently used in calculations gluon and quark distribution functions, which depend on the transverse momenta of the initial interacting particles, are shown. Various techniques to calculate the off-shell amplitudes of parton subprocesses are discussed. The application of the ${{k}_{{\text{T}}}}$-factorization approach to some QCD processes that are intensively studied in modern experiments at the LHC is considered, in particular, to processes of the single and double production of heavy quarks, as well as the inclusive and associated (correlated with one or two hadronic jets) production of direct photons (or heavy gauge boson) in proton collisions at high energies. A comparison of the obtained results with predictions made using the standard (collinear) approach in the next-to-leading order of perturbative QCD is presented. Basic capabilities and features of modern Monte-Carlo event generators PEGASUS, CASCADE and KATIE are also discussed.

Phys.Rev.D

Based on $(2.712\pm0.014)\times10^9$$\psi(3686)$ events collected by the BESIII collaboration, evidence of the hadronic decay $h_c\to K_S^0K^+\pi^-+c.c.$ is found with a significance of $4.3\sigma$ in the $\psi(3686)\to\pi^0 h_c$ process. The branching fraction of $h_c\to K_S^0 K^+\pi^- +c.c.$ is measured to be $(7.3\pm0.8\pm1.8)\times10^{-4}$, where the first and second uncertainties are statistical and systematic, respectively. Combining with the exclusive decay width of $\eta_c\to K\bar{K}\pi$, our result indicates inconsistencies with both pQCD and NRQCD predictions.

JHEP

A search for the fully reconstructed $B_s^0 \rightarrow \mu^+\mu^-\gamma$ decay is performed at the LHCb experiment using proton-proton collisions at $\sqrt{s}=13$ TeV corresponding to an integrated luminosity of $5.4\,\mathrm{fb^{-1}}$. No significant signal is found and upper limits on the branching fraction in intervals of the dimuon mass are set \begin{align} {\cal B}(B_s^0 \rightarrow \mu^+\mu^-\gamma) < 4.2\times10^{-8},~&m(\mu\mu)\in[2m_\mu,~1.70]\,\mathrm{GeV/c^2} ,\nonumber {\cal B}(B_s^0 \rightarrow \mu^+\mu^-\gamma) < 7.7\times10^{-8},~&m(\mu\mu)\in[1.70,~2.88]\,\mathrm{GeV/c^2},\nonumber {\cal B}(B_s^0 \rightarrow \mu^+\mu^-\gamma) < 4.2\times10^{-8},~&m(\mu\mu)\in[3.92 ,~m_{B_s^0}]\,\mathrm{GeV/c^2},\nonumber \end{align} at 95% confidence level. Additionally, upper limits are set on the branching fraction in the $[2m_\mu,~1.70]\,\mathrm{GeV/c^2}$ dimuon mass region excluding the contribution from the intermediate $\phi(1020)$ meson, and in the region combining all dimuon-mass intervals.