The "Nadya" compact precision spectrometer, currently under development at MEPhI (National Research Nuclear University), is designed to detect and identify directional charged-particle fluxes in the energy range from several tens to several hundred MeV. This energy range is of interest for the search for and detailed study of heliogeophysical phenomena, Earth's magnetospheric physics,...
The Monte Carlo event generators HYDJET and HYDJET++ are widely used to simulate high-energy heavy-ion collisions. This study compares their predictions with LHC measurements in Pb-Pb collisions at the LHC Run 3 energy 5.36 TeV in c.m.s. per nuclear pair. Charged-particle pseudorapidity spectra and multiplicity as a function of collision centrality are investigated. It is found that both...
In this paper we revisit Primordial Black Holes (PBHs) clusters as Dark Matter (DM) candidates. Here we present continuation of our previous work, extending the analysis. The analysis is devoted to re-consideration of constraint on PBH abundance from stellar cluster observation in dwarf galaxy Eridanus II. We take into account non-trivial density profile of PBH clusters in order to re-estimate...
In this project, we consider the Einstein-Maxwell gravity to describe the color superconductivity in the odd dimensional SU(N_c) arbitrary gauge theory in the boundary (even dimensional bulk). We study the equation of motion of the color superconductivity in different dimension bulk and the number of color.
Comparison of energy spectra of electrons and antineutrinos can help in understanding the mechanism of beta decay, which is not fully clear yet. Measuring an antineutrino spectrum from a known beta isotope requires an experiment with a large, high-resolution detector and a powerful source. Mirror symmetry can be checked by measuring the antineutrino spectrum and comparing it to the beta one....
A general understanding has emerged regarding the processes governing a wide range of nuclear reactions, particularly fission—see, for example, the review in [1]. Based on this understanding, computer codes have been developed to calculate total and partial cross-sections for the interaction of nuclei with light nuclear particles, specifically neutrons. All such codes rely on models describing...
Development of compact pocket-style electron accelerators meeting safety regulations is a complementary task requiring stable, reliable, and reproducible particle sources with controllable parameters. We employed a new approach for pyroelectric accelerator operation - periodically varying temperature of lithium tantalate (LiTaO3) crystal. It enables to generate stable quasi-continuous electron...
The processes of paired charmonium and bottomonium production in Z-boson decays are investigated within the relativistic quark model. Various decay mechanisms
are examined, and relativistic decay amplitudes are constructed, taking into account
the relative momenta of heavy quarks. Decay widths are calculated for various mechanisms in the nonrelativistic approximation and taking into account...
To measure cumulative beta-particle spectra of uranium and plutonium fission products, the BETA experimental facility is located at the output of the 11th neutron beam of the research reactor at the National Research Center Kurchatov Institute. The experiment simultaneously measures beta-particle spectra from uranium and plutonium targets, as well as the background spectrum, in the same...
We study the scattering of twisted neutrons with orbital angular momentum (OAM) from nuclear targets. A theoretical model is developed for Laguerre-Gaussian neutron states, accounting for nuclear and electromagnetic interactions and their interference.
We show that OAM and beam localization significantly modify the differential scattering cross section, while spatially inhomogeneous...
Using perturbation theory for the fine-structure constant α and the electron-to-
muon mass ratio, we calculate new contributions to the hyperfine structure of the
ground state of the muon-electron helium atom. Compared to our previous results,
we incorporated new corrections in the second order of perturbation theory. This
calculation reduces the discrepancy between the theoretical value and...
We discuss the signal readout system for cryogenic CsI(pure) scintillation detector of tritium neutrino. This detector is constructed in the frame of SATURN experiment for search of electromagnetic properties of neutrino in tritium decay. The elastic scattering of these neutrino at electrons in CsI scintillator deposits the energy below 1 keV that requires detection of extremely low signals....
Measurements of collective flow provide access to the equation of state (EOS) of dense baryonic matter and offer insights into the initial collision geometry. Strange particles, produced during the hadronic phase, serve as probes of the strangeness enhancement mechanism in heavy-ion collisions. The $\phi$ vector meson resonance therefore plays a key role in future studies; however, reliable...
This study investigates the stability of background conditions in the νGeN experiment at the Kalinin Nuclear Power Plant. It is demonstrated that fluctuations of the background count rate of the germanium detector inside the passive shielding are correlated with the intensity of photoabsorption peaks from radon-related gamma rays. Using data from periods with different intensity of these...
We present a theoretical proposal for measuring correlation functions in a quantum field system based on the use of quantum quenches. Using the examples of massive and massless scalar field theories, we show that a short-term perturbation of the system leads to a dependence of the further evolution of the average field on the initial state’s correlation functions. Considering two types of...
Experiments searching for elastic scattering of non-relativistic dark matter (DM) particles off nuclei lose sensitivity at DM masses below 1 GeV, since light particles transfer to nuclei energy below the detection threshold. Scattering off electrons enables partial probing of the region of lighter particles. Relativistic particles can arise from the acceleration of DM by cosmic-ray particles,...
\begin{document}
\title{Understanding of electromagnetic and gravitational form factors for nucleon and $\Delta$ with pion meson cloud}
\newcommand{\email}[1]{\thanks{\href{mailto:#1}{#1}}}
\author[a,b]{Jiaqi Wang\email{jqwang@ihep.ac.cn}}
\author[c]{Dongyan Fu\email{fudongyan@impcas.ac.cn}}
\author[a,b]{Yubing Dong\email{dongyb@ihep.ac.cn}}
\affil[a]{Institute of High Energy Physics,...
Searches for submicrosecond and nanosecond optical transients are motivated by studies of rapid astrophysical processes and the search for extraterrestrial intelligence (SETI). Imaging atmospheric Cherenkov telescopes can be used to search for such transients during regular observations. Coincident signals from multiple telescopes, combined with image analysis, help identify candidate events...
In the dissociation of neutron-rich krypton, neutron emission accompanies the formation of charged fragments. Information on neutron multiplicity and angular distributions complements the analysis of α-particle correlations and helps characterize the composition and kinematics of the breakup products. Estimating the sensitivity of nuclear emulsion to this neutron component is therefore an...
The presented work discusses the features of the developed fully connected three-layer neural network for data analysis. The model was created to process .root data from the open CERN data library. The goal of this model is to identify the rare process of B+-meson production and its subsequent decay: B⁺ → J/ψ + K⁺, J/ψ → μ⁺ + μ⁻.
B⁺ mesons contain a b quark and are heavy, unstable particles....
Atmospheric muon spectra are used in a range of cosmic-ray studies, including investigations of extensive air showers, atmospheric particle production, and atmospheric neutrino fluxes, as well as for validating particle-transport and cascade models. In particular, the spectrum is critical for estimating matter distribution in muography. For practical applications, compact analytical...
We present a detailed comparison of Bayesian criteria with three non-informative priors - flat, Jeffreys, and scale-invariant - for testing a signal against an unknown background and compare them with the classical frequentist Li-Ma approach in the On/Off problem. We perform Monte Carlo simulations for various background levels and evaluate the Li-Ma and Bayesian criteria by their Type I error...
In this work, we focused on the conditions at the Cosmic Dawn, before cosmic reionisation. We place new constraints on the fraction of the neutral hydrogen of the intergalactic medium at z = 9.02-14.18, after analysing Lyman-alpha emission (including upper limits) from 94 galaxy sources. Of these sources, there were 91 3σ upper limits and 3 detections. This analysis was done using JWST data...
We investigate the production of millicharged particles (mCPs) by the Schwinger mechanism in thunderstorms in the atmospheres of different planets in the Solar system. We consider a thundercloud as a giant capacitor that can be discharged in two ways: either by lightnings or by mCP production. Taking into account the observation of lightning strikes, we establish the constraints on the charge...
Modern nuclear databases such as NuDat 3 and ENSDF provide extensive experimental
information on level energies, spins, parities, and decay modes. However, these databases
lack tools for automated comparison with theoretical predictions and do not provide
complete single-particle level schemes, particularly for exotic nuclei far from stability.
In this work, we present a systematic study of...
TAIGA-100 is a project of a large-scale astrophysical complex designed to solve a wide range of fundamental problems in gamma astronomy in the energy range from 300 GeV to above 1 PeV, cosmic ray (CR) physics from 100 TeV to 10 EeV, particle astrophysics, neutrino physics, and interdisciplinary research. The complex will include several types of detectors for registering different components...
We describe the experimental setup and data analysis procedure developed for measuring polarization correlations of 511 keV annihilation photons after Compton scattering at angles from 60° to 120°. The setup consists of two arms of Compton polarimeters with intermediate pre-scatterers placed in front of the main scatterers. Each arm is equipped with a ring of 16 scintillation counters covering...
We present a prototype of a modular reactor antineutrino detector based on the inverse beta decay (IBD) reaction ($\bar\nu_e + p \rightarrow n + e^+$). Each module operates as an independent spectrometer based on a solid plastic scintillator block measuring $(700 \times 50 \times 50) \text{ mm}^3$, optically coupled to two vacuum photomultiplier tubes (PMTs) with an effective photocathode...
In heavy-ion collisions at a beam energy of 3.8A GeV, a dense baryonic medium is formed in the nuclear overlap zone. The anisotropic flow of produced particles provides insight into the transport properties and equation of state (EoS) of this strongly interacting matter. This contribution reports preliminary results on the directed flow ($v_{1}$) of protons in Xe+Cs(I) collisions at 3.8A GeV,...
Neutrinos emitted during the gravitational core collapse supernova are the most direct probe of processes in the stellar interior which are inaccessible to electromagnetic observations. Interpretation of signals from future flares by, e.g., JUNO, DUNE, IceCube-Gen2, KM3NeT, Baikal-GVD detectors, requires consideration of a complex set of physical effects [1] including generation of...
The energy and timing resolution of the Russian-made Topaz-M microchannel-plate photomultiplier tube (MCP-PMT), developed and manufactured by Baspik, were experimentally studied. The coincidence time resolution of the Topaz-M MCP-PMT was measured for the first time, while its energy resolution was studied with LaBr₃:Ce and GAGG scintillators using gamma-ray sources in the 511-1275 keV energy...
This study investigates thermonuclear nucleosynthesis within hypothetical hot primordial regions of the early Universe, which are separated from the Hubble expansion and confined within domain walls. We present a numerical model simulating the evolution of nuclide concentrations at constant extreme temperatures exceeding 5 MeV. Under these conditions, the confinement of neutrinos makes weak...
This study presents an analysis of Nuclear Track Emulsion (NTE) exposed
to an extracted $^{124}$Xe$^{54+}$ beam at around 300 MeV per nucleon at the JINR
Nuclotron, conducted within the framework of the BECQUEREL project[1].
The primary aim was to characterize the beam profile and its uniformity, and
to determine the Bragg peak position, in support of applied research in electronic components...
The uncertainty associated with reactor fission fractions is an important contribution to precision predictions of the antineutrino flux and to antineutrino-based reactor monitoring. We evaluate the uncertainties and correlations of the fission fractions of $^{235}U$, $^{238}U$, $^{239}Pu$, and $^{241}Pu$ for a VVER-1000 reactor and propagate them to the calculated electron-antineutrino flux....
A joint study of multi-particle pseudo-rapidity correlations and event-by-event fluctuations in the distributions of secondary particles and fragments of the target nucleus and the projectile nucleus was carried out in order to search for correlated clusters of secondary particles. An analysis of the collisions of the sulfur nucleus with photoemulsion nuclei at an energy of 200 A・GeV is...
FPGA-BASED MUON REGISTRATION CHANNEL FOR POSITIONING SYSTEM
M. A. Lapshin¹, A. V. Kantsyrev¹, A. A. Golubev¹, A.V. Bognadov¹
1NRC «Kurchatov Institute», Russia
E-mail: lapshin.mm.aa@gmail.com
Cosmic-ray muons are a natural source of penetrating particles that can be used for positioning and navigation in underground environments where conventional positioning systems have limited...
We propose the quark model of nuclear structure where quark correlations lead to nucleon-nucleon correlations and arrangement of them into lattice--like structure. The model is based on the quark model of nucleon structure in which valence quarks are strongly correlated within a nucleon (SCQM). Nuclei are built by junctions of SU(3) color fields of two quarks of neighboring nucleons....
The High-Granularity Neutron Detector (HGND) is a new detector system in the BM@N experiment at the Nuclotron (JINR, Dubna), designed for the identification and measurement of neutron energies produced in nucleus-nucleus collisions at energies up to 4 AGeV. This talk covers progress in pre-production verification and performance studies of the full-scale active layers of the detector, as well...
Flat rotation curves of galaxies suggest extra gravity at galactic scales, which is usually explained by dark matter (DM). However, astrophysicists
([P. Kroupa et al][1])
point to facts and data that contradict the DM hypothesis. Instead, the MOND model is advocated. The baryonic Tully–Fisher relation
$\log M_ {\rm bar} = c + b \log V_{\rm flat}$ links the baryonic mass of spiral galaxies...
Heavy ions within the Galactic Cosmic Ray (GCR) spectrum present a primary challenge for radiation risk assessment in deep-space exploration and astroparticle physics. Accurate description of their biological effectiveness requires multi-scale Monte Carlo simulations that account for both nanoscale stochastic ionization patterns and macroscopic energy deposition in target volumes.
In this...
Extreme energy release in astrophysical sources, including the Sun, is associated with the acceleration and interaction of elementary particles—specifically, with the conversion of magnetic field energy. Consequently, the systematic study of radio emission from these sources with high angular resolution makes it possible to identify the mechanisms of particle acceleration, plasma heating...
Secondary electron emission is the process of electron emission from the surface of a material (target) under bombardment by beams of charged particles and heavy ions. The study of this process is challenging due to the need for accurate measurements of both the incident beam current and the total current of secondary electrons emitted from the target. Secondary electron emission is a surface...
The search for CP violation in the lepton sector is one of the central goals of modern neutrino physics, motivated by the need to explain the matter–antimatter asymmetry of the Universe. In long-baseline accelerator experiments, the interpretation of neutrino and antineutrino appearance signals is complicated by matter effects: coherent forward scattering in the Earth can mimic or modify...
The next generation water Cherenkov detector Hyper-Kamiokande in its outer part will utilize light-collection modules composed of a PMT surrounded by a plexiglass-based WLS plate. Success of the rich physics program of the experiment that ranges from energetic atmospheric and accelerator and down to cosmic and solar neutrinos involves strict requirements and control of the radiopurity of the...
A modernization of the temperature control system for the M31 spectrometric magnet of the SPASCHARM experiment at the U-70 accelerator is presented. The transition to a multitasking architecture based on FreeRTOS, together with the use of EPICS, is aimed at improving the modularity, versatility, and scalability of the slow control system. The new architecture enables independent execution of...
TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) is a hybrid air-shower observatory located in Eastern Siberia and designed to study high-energy gamma rays and cosmic rays. The TAIGA-IACT imaging atmospheric Cherenkov telescopes operate at TeV energies, where a key challenge in gamma-ray observations is the suppression of the hadronic background, which significantly...
High-energy cosmic-ray muons penetrating deep underground undergo stochastic interactions in rock and can produce a significant secondary particle component accompanying the surviving muon. This effect becomes particularly important at muon energies approaching the PeV range, where radiative and photonuclear processes may result in large energy transfers and production of energetic secondary...
Machine-learning-based calorimeter reconstruction is usually optimized under fixed detector conditions, whereas detector response can be affected by dead channels, local readout failures, gain drift, and noise. We study whether exposing a reconstruction model to several simulated failure modes during training improves its robustness compared with training on a single corruption type. The study...
Muonography is an innovative method for investigating the internal structure of massive natural and industrial objects using fluxes of high-energy atmospheric muons. Its range of applications is broad, extending from mineral exploration to the assessment of natural and man-made risks to civil infrastructure. In geology and geophysics, it serves as a promising tool that complements traditional...
Muon reconstruction in the Baikal-GVD neutrino telescope requires inferring particle parameters from sparse, irregularly distributed optical signals. We investigate graph neural networks and transformer architectures for reconstructing muon direction and track position, using classical track fitting as a reference. Muon energy estimation is considered as an additional task.
Using Baikal-GVD...
A number of current and future neutrino experiments are devoted to the detection of astrophysical neutrinos. Neutrino interactions with dense matter and strong magnetic fields peculiar to astrophysical environments, such as supernova explosions, are expected to cause considerable effects in the neutrino flavour evolution. One of the interesting effects is damping of the neutrino oscillations...
Isotope and velocity distributions of neutron-rich isotopes produced in peripheral heavy-ion collisions are investigated using the high-luminosity, strong-focusing kinematic fragment separator COMBAS at the U400M cyclotron facility. Full systematic study of the short-lived isotopes produced in collisions induced with 18O (at 35 MeV/nucleon), 22Ne (at 42 MeV/nucleon), and 40Ar (at 36...
IGR J17285−2922 is a very faint transient low-mass X-ray binary whose compact object has not yet been securely identified. Its consistently hard X-ray spectra during detected outbursts and its multiwavelength behaviour favour a black hole interpretation, although a neutron star primary has not been excluded. We investigate the nature of the compact object using two archival NICER observations...
The report presents the results of a study of the processes of paired gravitino production at the Large Hadron Collider (LHC). The observability of such processes under LHC conditions is assessed. In the model under study, the gravitino is the LSP and is also considered a candidate for a dark matter particle.
The study examines the applicability of the commercially available silicon PIN photodiode BPW34 without internal amplification as a photodetector for scintillation light. Specifically, the photodiode response to cosmic-muon-induced light flashes is investigated when optically coupled to a bismuth germanate crystal (BGO) and a plastic scintillator. The electronic readout is utilized as a means...
Polymer Composite Scintillators Based on Halide Perovskite Nanocrystals for X-Ray Imaging
A. A. Knysh$^1$$^,$$^2$, P. M. Sokolov$^1$$^,$$^2$, V. V. Sosnovtsev$^1$, P. S. Samokhvalov$^1$$^,$$^2$
$^1$National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow, 115409 Russia
$^2$Life...
In a baryon-asymmetric Universe, primordial antimatter domains arise from inhomogeneous baryogenesis driven by the Pseudo-Nambu-Goldstone Boson field during inflation. Their evolution is governed by the competition between Hubble expansion and microphysical erosion of the domain boundary via annihilation with surrounding matter.
The domain, however, is not homogeneous. Stochastic dynamics of...
Lorentz invariance violation (LIV) can modify electromagnetic interactions at ultra-high energies and thereby affect the development of extensive air showers (EASs). We study a subluminal photon-sector LIV scenario in which Bethe–Heitler pair production is suppressed. Using LIV-modified EAS simulations, we model the resulting changes in the depth of shower maximum, $X_{\max}$, and...
The report describes a proportional counter developed for the search for cold dark matter, presumably consisting of hidden photons, in the PHELEX experiment (PHoton-ELectron EXperiment). The two-cathode counter is aimed at searching for diurnal variations in the count rate of single electrons emitted from the surface of the metal cathode of the proportional counter, presumably as a result of...
The processes of solar neutrino scattering by the H and He atoms are considered. Along with the weak neutrino-electron interaction, the electromagnetic interaction due to the neutrino magnetic moment $\mu_\nu$ is also taken into account. This study can be useful for the analysis of data from neutrino as well as dark matter experiments. Specifically, it could be useful to estimate the...
In various microscopic string models (see, e.g., [1–8]), the Schwinger mechanism [9, 10]—which features a characteristic Gaussian exponential—is used to describe particle transverse-momentum spectra. On the other hand, experimental data on inclusive hadron production spectra exhibit pronounced thermal behavior. A. Bialas [11] proposed resolving this contradiction by accounting for fluctuations...
The possible formation of deconfined quark matter in the cores of massive neutron stars and magnetars provides an extreme environment for studying quarkonium in ultra-strong magnetic fields. In this work, quarkonium states and their annihilation through the q q̅ → 2γ channel in hot magnetized quark matter are investigated, taking into account Landau-level quantization and the interaction with...
Abstract
Subthreshold production of ΛΛ pairs in nucleus–nucleus collisions is largely unexplored and is of particular interest for studying strangeness-production mechanisms in dense baryonic matter.
In 2023, the fixed-target BM@N experiment at the NICA–Nuclotron accelerator complex collected data from Xe + CsI collisions at a beam kinetic energy of 3.8A GeV. This work presents the...
We investigate resonance phenomena in kink-antikink collisions in
(1+1)-dimensional scalar field theories with higher-order polynomial
potentials. Particular attention is paid to the mechanism of energy
exchange between the translational motion of the kinks and vibrational
modes of the kink-antikink system.
Numerical simulations reveal a nontrivial dependence of the collision
outcome on the...
One of the scientific goals of the LVD experiment is the search for neutrinos. The study of neutrinos is important for understanding particle physics and processes occurring in astrophysical objects. In this work, high-energy single-muon events are considered under the assumption that some upward-going events may be related to interactions of muon neutrinos.
An algorithm was developed to...
Semiconductor radiation detectors provide high energy resolution, with silicon PIN photodiodes being widely utilized due to their technological simplicity and affordability. This study investigates the feasibility of using the commercially available BPW34 silicon PIN photodiode as a low-cost semiconductor detector for X-ray and soft gamma-ray spectrometry. A method for determining the optimal...
This work presents the results of an experiment performed at the ACCULINNA-2 fragment separator (FLNR JINR) aimed at studying the elastic and inelastic scattering of ^{6}He + ^{4}He over a wide angular range. A secondary 6He beam with an energy of 151 (168) MeV irradiated a 5.5-mm thick cryogenic gaseous ^{4}He target maintained at a temperature of 12 K and a pressure of 1 (2) atm. The...
DANSS is a highly segmented antineutrino detector located at the Kalinin Nuclear Power Plant. The main goal of the experiment is to search for reactor antineutrino oscillations into a hypothetical sterile neutrino state. DANSS has achieved the most stringent model-independent limits around Δ𝑚₁₄² ≈ 1 eV². The experiment searches for reactor antineutrino oscillations into a sterile state by...
A new high-statistic analysis of the semileptonic decay mode of charged kaon to neutral pion, antimuon and muon neutrino $K^+ \to \pi^0 \mu^+ \nu_\mu$ in OKA experiment is presented. The study includes preliminary results of kaon decay form-factor measurements and constraints on the Type-II 2HDM parameters.
The decoherence curve of muon bundles in extensive air showers is investigated in this work using the FANSY 2.0 package. Using the Monte Carlo method, the development of cascades in the atmosphere is simulated for different types of primary particles (protons and iron nuclei), a wide range of initial energies and zenith angles. The dependence of the spatial distribution of muons at the...
CENNS-10 is a single phase liquid argon (LAr) scintillation detector deployed by the COHERENT collaboration at the Spallation Neutron Source located at the Oak Ridge National Laboratory in 2017. The detector was designed to study the Coherent Elastic Neutrino-Nucleus Scattering (CEνNS) using the high-quality pion-decay-at-rest neutrino source. The collaboration reported the observation of...
This work is devoted to the restoration of the KALIF-8 automated test bench for evaluating the characteristics of photomultiplier tubes of various sizes. During the work, cable lines were replaced, the electronics were updated, and the main components of the measurement system were calibrated. The software for centralized control of the test bench was configured.
During the experimental...
The interest of the scientific community on supernovae (SNe) has increased in the recent years for several reasons. Mostly they are the advances in the understanding of the SN phenomena obtained with the intensive study of nearby SNe, first of all SN 1987A, which have raised new more fundamental questions with regard to progenitor evolution, explosion mechanism and nucleosynthesis.
The Open...
Majorana neutrino oscillations in a magnetic field are considered using the wave packets formalism. The dispersion relation for neutrinos with non-zero transition magnetic moments propagating in a magnetic field is found in the two flavour case. It is shown that for Majorana neutrinos propagating in a magnetic field the coherence length coincides with the coherence length for neutrino...
Studies of solar activity and prediction of the effects of coronal mass ejections and high-energy radiation from solar flares on near-Earth space and the biosphere are among the major objectives of solar and solar–terrestrial physics. The GRISP (Gamma -, X-radianion and Solar Protons) instrument suite is designed to measure the energy and time distributions and intensities of electromagnetic...
