Cosmic ray research at the Physical Institute of the USSR Academy of Sciences motivated the construction of the Synchrophasotron. For this purpose, the Electrophysical Laboratory of the USSR Academy of Sciences was founded in 1953, which became part of JINR in 1956. The most important milestones in the development of the Synchrophasotron itself and experiments on it are presented. Lessons and...
The report presents the history of the construction of the Nuclotron and the results of experiments conducted on it.
Recent results, present status and futures perspectives in neutrino physics will be presented. In the study of neutrino oscillations an emphasis will be put on a search for CP violation and determination of the neutrino mass ordering. The results obtained in current long baseline accelerator experiments T2K and NOvA will be discussed. The brief overview and status of the next generation...
The report presents the results of the development of the approach to the study of relativistic nuclear interactions in the four-velocitiy space using the similarity principle.
The essence of the modification of the self-similar approach consists in the inclusion of quark-gluon dynamics in the generation of hadrons in the nuclear-nuclear interactions in the central rapidity region. Inclusive...
In 1963 first quasars were discovered which are supermassive black holes. The Kerr solution is a key component for models of active galactic nuclei (AGNs). In 1968 first pulsars were discovered and their model as rotating neutron stars (NSs) had been proposed. NSs were observed in different spectral band of electromagnetic radiation. In addition, a neutrino signal had been found for SN1987A....
The measurement of exclusive $e^+e^-$ to hadrons processes
is a significant part of the physics program of the CMD-3 experiment,
aimed to improve the calculation of the hadronic contribution to the
muon $g−2$ and to study the intermediate dynamics of the processes. We
present the most recent results obtained by using the data set of
about 700 pb^-1 collected by the CMD-3 detector at the...
In addition to $\Lambda$ hyperon, new data on $\Sigma$ hyperons production are compared to different Monte-Carlo models and contribute to the understanding of hadron production mechanisms.
The first measurements of the transverse momentum ($p_{\rm{T}}$) spectra of $\Sigma^{0}$ and $\bar{\Sigma}^{0}$ hyperons in pp collisions at $\sqrt{s} = 7$ TeV at the LHC are presented. The...
The STAR experiment at Brookhaven National Laboratory was built to study the behavior of strongly interacting matter at high collision energy. One of the primary goals for STAR’s experimental program at the Relativistic Heavy-Ion Collider (RHIC) is the investigation of Quantum chromodynamics (QCD) phase properties. These include the search for the location of QCD critical point and the...
Relativistic heavy-ion collisions provide a unique opportunity to
study the expansion dynamics and the transport properties of the produced
strongly interacting matter. The presentation will review the recent results of anisotropic
flow measurements for collision energies from √sNN = 5.2 TeV to 2 GeV
The generalized parton distribution functions (GPDs) of spin-3/2 particles are given 【1】. Sum rules of those GPDs and structure functions of the systems are obtained. As a typical example, we numerically calculate the electromagnetic and gravitational form factors of the spin-3/2 baryon (like \Delta or \Omega) by using a quark-diquark approach【2-4】. Lattice calculation results are considered...
Deviation of the cross section for the nuclear reaction X(a, b)Y from the Gamow formula due to an interaction additional to the Coulomb one in the entrance channel has been analyzed. It is shown that the reaction cross section has an oscillating structure at low energies. If the maximum of the first oscillation is close to the threshold of the channel a+X, it has a resonance behavior. To...
Some highlights on studies of strangeness and charm in heavy ion collisions by ALICE at LHC
Grigory Feofilov, Saint-Petersburg State University, RF,
(on behalf of the ALICE Collaboration)
The formation of a strongly interacting medium of deconfined quarks and gluons, known as the quark-gluon plasma (QGP), that occurs in the ultrarelativistic nuclear collisions at the LHC, can
be...
This work is devoted to the search for lambda hyperons and short-lived neutral kaons after collision of Xe beams with a CsI target at E = 3.9 AGeV at the BM@N experiment (JINR, Dubna). Simulation, reconstruction and filtering of 100,000 events were carried out. Peaks in the invariant mass distribution corresponding to lambda hyperons and kaons were obtained. Efficiency as a function of...
In the BM@N experiment at the Nuclotron accelerator, the production of $\pi^+$ and $K^+$ mesons in collisions of argon ions with an energy of 3.2 GeV with solid targets of C, Al, Cu, Sn, and Pb was studied. Yields are obtained in kinematic variables in terms of rapidity and transverse momentum. The estimation of the parameters of inverse slopes and multiplicities is performed. The results are...
Neutron stars have the density of the of the nuclear one, so the methods from the nuclear and particles physics can be used to describe them. However at high densities reached inside neutron stars an additional sensitivity to the certain properties of the baryonic interaction can appear.Therefore studying of neutron stars may be of great importance for understanding the properties of baryonic...
NICA (Nuclotron-based heavy-Ion Collider fAcility) is a new flagship project at JINR (Dubna, Russia) aimed at the construction of a new accelerator complex for heavy ions and polarized particles [1]. Collisions of relativistic ions with energies up to 11 GeV (center-of-mass) will be studied with the MultiPurpose Detector MPD providing accurate precise tracking and reliable particle...
We investigate the finite-temperature structure of ghost and gluon propagators within an approach based on the rainbow truncated Dyson-Schwinger equations in the Landau gauge. The method early used for modeling quark, ghost and gluon propagators in vacuum is extended to finite temperatures. In Euclidean space, within the Matsubara imaginary-time formalism, it is necessary to distinguish...
Obtaining quality physics results requires high-statistics
data with low background contamination. The task of maximizing
the signal as well as accurate estimation of combinatorial background
is especially important at the start-up of the experiment when the
amount of data is rather limited. The MPD experiment at the NICA collider
will have to deal with such issues in its first run.
...
SHiP and the associated SPS Beam Dump Facility is a new general-purpose experiment proposed at the SPS to search for "hidden" particles as predicted by a very large number of recently elaborated models of Hidden Sectors which are capable of accommodating darkmatter, neutrino oscillations, and the origin of the full baryon asymmetry in the Universe. The detector incorporates two complementary...
Results on determination of the microscopic Hubble constant for pions and nucleons in Au+Au collisions at $\sqrt{s_{NN}} = 7.8$ GeV for a range of times and three impact parameters are presented and discussed. The data are simulated within PHSD model. A typically used method based on the fit of the velocity profile is considered in detail. Also a new method for determination of the Hubble...
Vortical structure of hot-dense matter in heavy ion collisions can be observed through global polarization of emitted particles.
Hyperon's weak decays provides opportunity to measure this phenomenon. Global polarization of $\Lambda$ hyperons was measured by the STAR experiment at RHIC for Au+Au collisions with $\sqrt{s_{NN}}$ = 3-200 GeV and at the LHC for Pb+Pb collisions with...
During past 30 years in high-energy physic experiments, the detector systems have actively exploited technology based on silicon pixel sensors. Today and in the coming years many of collider’s experiments use pixel detectors as main part for particle tracks identification.
To solve modern tasks in elementary particle physics field (heavy flavor physics, study of charmonium yields at very low...
Using first-principle numerical simulations of the lattice SU(3) gauge theory, we calculate the isothermal moment of inertia of the rigidly rotating gluon plasma. We find that the moment of inertia unexpectedly takes a negative value below the "supervortical temperature" $T_s = 1.50(10) T_c$, vanishes at $T = T_s$, and becomes a positive quantity at higher temperatures. The negative moment of...
One of the main goals of the beam energy scan physical programs with heavy ions in the range of 2-3.5 GeV is to study the high-density equation of state (EOS) and the search for an onset of a phase transition in dense baryonic matter. Anisotropic flow coefficients are one of the observables that are commonly used in such studies.
Generally, at such energies one can define EOS of the dense...
The coherent inelastic processes of the type $a \rightarrow b$, which
may take place in the interaction of hadrons and $\gamma$ quanta with
nuclei at very high energies ( the nucleus remains the same ), are
theoretically investigated. For taking into account the influence of
matter inside the nucleus, the optical model based on the concept of
refraction index is applied .
Analytical...
Currently, there is no experimental evidences of the violation of the spatial parity (P) conservation in strong interactions. However, the in the QCD theory, the P-breaking term (so-called $\theta$-term) can be included, with tight limits on the $\theta$ parameter value. However, in the medium with high temperature and at large topological fluctuations [1] of QCD fields, expected in collisions...
One of the main goals of the Relativistic Heavy-Ion Collider is to investigate the properties of quark-gluon plasma (QGP). Azimuthal anisotropy of hadrons produced in relativistic collisions is considered as a good tool to study QGP’s properties. It can be characterized using Fourier coefficients, where the second coefficient is the elliptic flow ($v_2$). Thus, hadron elliptic flow...
We analyse and give the important details on the Gorishni-Isaev (massless) vacuum integrations. In particular, it has been shown how the delta-function represents either UV-regime or IR-regime. In the case of vacuum integration, we advocate the use of sequential approach to the singular generated functions (distributions).The sequential approach is extremely useful for many practical...
The mass formulas and decay constants of electrically charged and strange pseudoscalar mesons are analyzed within the combined framework of Nambu -- Jona-Lasinio model and the $1/N_c$ expansion up to $\mathcal O(1/N_c^2)$. The light quark masses explicitly violating $SU(3)_L\times SU(3)_R$ chiral symmetry of the strong interactions are taken to be of order $\mathcal O(1/N_c)$. The...
More than 360 000 patients were treated at 100 proton and also at 8 heavy-ion cancer therapy facilities worldwide [1]. While beams of protons, $^{4}$He and $^{12}$C nuclei are very effective in killing deep-seated solid tumors, some damage to surrounding healthy tissues is unavoidable and must be reduced. It has been proposed [2,3] to use arrays of thin proton beams, spatially fractionated at...
The associated production of $J/\psi+\gamma$ in proton-proton collisions is discussed theoretically for about 30 years [1], so it is relevant to make predictions for modern colliders energy: NICA ($27$ GeV), RICH ($200$ GeV), LHC ($13$ TeV). The differential cross section predictions were performed analytically and also using the KaTie event generator [2] both in an improved Color Evaporation...
A synthesis of the research developed in the frame of E&T collaboration, aimed to identify the conditions which maximize the efficiency of an accelerator driven subcritical reactor (ADSR) are presented. Experiments performed in the extended U target “Quinta” irradiated with deuteron and 12C beams with energies 0.5-4 AGeV and simulations realized with the toolkit Geant4 in enriched targets were...
The study of the high-density equation of state (EOS) and the search for a possible phase transition in dense baryonic matter is the main goal of beam energy scan programs with relativistic heavy ions at energies $\sqrt{s_{NN}}$ = 2-5 GeV.
In this work, we discuss the layout of the MPD (NICA) experiment in the fixed target mode and the anticipated performance for differential anisotropic flow...
In this talk, we explore the potential of azimuthal flow as a tool for investigating color string fusion in proton-proton collisions.
Our approach is based on a detailed simulation of the longitudinal and transverse dynamics of strings leading to their subsequent fusion and decay [1,2]. Using model calculations, we demonstrate that the azimuthal anisotropy of the produced hadrons is...
Experiments on the study of the neutron spectrum in accelerator systems are of considerable interest. Detailed simulation of an experimental target is a significant phase at preparing for experiments on targets irradiation.
Simulation of a ~21 t depleted uranium target irradiated by 1…10 GeV proton and deuteron particles with the help of FLUKA simulation package was carried out. Neutron...
A.V. Anufriev
Samara National Research University, Samara, 443086, Russia
V.A. Saleev
Samara National Research University, Samara, 443086, Russia and
Joint Institute for Nuclear Research, Dubna, 141980 Russia
Study of charmonium production at high energy in proton-proton collisions is important test of perturbative QCD, factorization approach and hadronization model in a heavy quark...
In the relativistic heavy ion collisions at the beam energy of a few GeV the strongly interacting matter is created at high baryon densities and relatively low temperatures. Azimuthal anisotropy of the produced particles provides a valuable insight into the properties of this form of matter. In this work, we discuss the layout of the upgraded Baryonic Matter at Nuclotron (BM@N) experiment...
Following recent results, an overview of fractional analytic QCD beyond the leading order is presented. We demonstrate various representations, details of their derivation, and show the applicability of analytic QCD to the study of the Bjorken sum rule and the decay of the Higgs boson into a bb pair.
We have studied hidden-charm strong decays of the charmonium-like resonant state $Y(4320)$ within the framework of a confined quark model by interpreting the resonance as a four-quark state with molecular-type interpolating current. The strong decay of $Y$ into a vector and a scalar resonance, with the latter decaying, subsequently to a pair of charged pseudoscalar states, has been...
Radiobiological research in Laboratory of Radiation Biology focusses on addressing both fundamental and applied problems of modern biology and medicine and relies on the availability at JINR of a wide range of radiation sources, including beams of heavy ions of various energies.
In the context of fundamental aspects, our research focusses on understanding of the key physical and biological...
Rare $B$-meson decays due to the Flavor Changing Neutral Current (FCNC) $b\to s$ and $b\to d$ quark transitions are quite sensitive to New Physics effects because of the smallness of their decay width. The $b\to s$ transition has been intensively studied both experimentally and theoretically thanks to an enormous sample of $B$-mesons produced at electron-positron and hadron colliders....
The study of nuclear multifragmentation in the relativistic energy region provides valuable insights into nuclear clusters and fragmentation characteristics. In this context, the Nuclear Track Emulsion (NTE) detector has been used in the BECQUEREL experiment to analyse the cluster structure of light nuclei, including radioactive ones [1]. NTE detector possess the significant advantages over...
The size and evolution of the matter created in a relativistic heavy-ion collision strongly depend on the collision's initial geometry, defined by centrality. Experimentally the centrality of collisions can be characterized by the measured multiplicities of the produced particles at midrapidity or by the energy measured in the forward rapidity region, which is sensitive to the spectator...
Gell-Mann-Low functions in quantum field theory are usually defined as asymptotic expansions over a small coupling. However their behavior at large coupling is of principal interest, since this behavior sheds light on the general properties of the coupling parameter as a function of a scale variable. We developed an approach, called self-similar approximation theory, allowing for the...
A.A. Chernyshev
Samara National Research University, Samara, 443086, Russia
V.A. Saleev
Samara National Research University, Samara, 443086, Russia and
Joint Institute for Nuclear Research, Dubna, 141980 Russia
In the article, we study associated production of heavy quarkonia and $D$ mesons in the improved color evaporation model using the high-energy factorization as it is...
Glauber approach is widely used for describing multiparticle production in the interactions involving hadrons and nuclei in a wide energy range [1-2]. For the more detailed description of nuclear interaction features, this model is increasingly being used at the parton level [3-6], however, usually, the pp-interaction is given insufficient attention.
Before application of the model to...
Nucleon associations (clusters) are one of the basic phenomena in atomic nuclei structure. Their simplest observable manifestations are the lightest He and H nuclei. Superpositions of the lightest clusters and nucleons form subsequent nuclei (including unstable $^8$Be and B), which act as constituent clusters themselves for more complicated nuclear systems. The phenomena of claster...
In the framework of the model with string fusion we study the correlations between multiplicities in two separated rapidity windows in pp collisions at LHC energies and compare the results with the data obtained by ALICE collaborations at CERN.
The Monte Carlo modelling in the framework of a quark-gluon string model were implies. The string fusion effects were also taken into account by...
A workable basis of quark configurations s^3, s^2p and sp^2 at light front has been constructed to describe the high-Q^2 behavior of transition form factors in the electroproduction of the lightest nucleon resonances. High quality data of the CLAS Collaboration are described in the framework of a model which takes into account mixing of the quark configurations and hadron-molecular states. The...
QED structure and fragmentation functions are systematically derived within the next-to-leading order approximation. DGLAP evolution equations are solved by iterations. Perturbative results are shown for electron parton distribution functions up to O(\alpha^3L^2), where L=\ln(\mu^2/m^e^2) is the large logarithm and \mu is the factorization energy scale. The results are relevant for the present...
Data-driven techniques are frequently used in high energy physics to get reliable estimate of backgrounds from object misidentification. Here, an approach to the estimation of the background induced by the misidentification of a jet as a photon, in short jet → γ, is presented. It is based on real and fake efficiencies of real/fake photons to pass the tight identification criteria. Selected...
The analysis of ALEPH data on femtoscopic correlations of two lambda-hyperons in Z-boson decays yields a very small source radius of 0.11+/-0.03 fm if taking into account only the repulsion due to the Fermi-Dirac quantum statistics. Such a small source radius is counter-intuitive in the string picture of particle production due to a moderate string tension of ~1 GeV/fm. It is shown that the...
The complete one-loop electroweak radiative corrections
to the cross section of the process
$e^{+}e^{-} \to e^{-}e^{+}(\gamma) $
are evaluated at low angles with the help of the SANC system.
Numerical results are given center-of-mass energy for the resonant energy of Z boson and 240 GeV in full phase space
with various experimental cuts.
The lastes run of the BM@N experiment conducted at the beginning of 2023 is officially a physics run, the main purpose of which is to obtain certain scientific results declared in the research program of the experiment.
Due to the increased event multiplicity, in comparison with previous experimental runs, the configuration of the inner tracker was appreciably upgraded: detection planes...
The study of the correlation between the multiplicity of charged particles and the average transverse momentum was carried out in proton-proton and nucleus-nucleus collisions from the SPS energy to the LHC energy [1]. Extending the experimental data from negative correlations at energies √s = 17–40 GeV to lower energies can lead to significant limitations for various theoretical models....
In the relativistic quark model, based on point form of poincare-invariant quantum mechanics, the form-factors of pseudoscalar meson radiative decay $P^{\pm}(q\bar{Q})\rightarrow \ell^{\pm}~\nu_{\ell^{\pm}}\gamma$ are investigated. It's show that taking into account constituent quark structure functions leads to numerical evaluation close to modern experimental data.
Recent results on a study of exclusive processes of $e^+e^-$ annihilation into hadrons with the SND detector at the VEPP-2000 collider at center-of-mass energies below 2 GeV are presented. In particular, we discuss new data on the processes $e^+e^- \to n\bar{n}$, $p\bar{p}$, $\eta\gamma$, $\omega\pi^0$, $\pi^+\pi^-\pi^0$, $\pi^+\pi^-\pi^0\pi^0\eta$.
In strangeness nuclear physics, exotic hypernuclei with a proton or neutron excess are of particular interest now. Such systems relatively poorly explored in experiment can be produced in heavy ion collisions, particularly at NICA complex developed at JINR. Studies of exotic hypernuclei allow to improve the understanding of subtle features of the hyperon-nucleon and hyperon-nucleus...
With the increasing luminosity of modern accelerators in high energy physics, the problem of fast modelling of elementary particle detectors is becoming increasingly important. One approach to fast detector modelling is generative machine learning models, among them Generative adversarial networks (GANs) offer the fastest sampling.
This paper discusses the application of GANs to fast...
The contributions to the lepton magnetic moment anomaly, $a_L=(g-2)_L/2$, $L=e\ , \mu $ and $\tau$, generated by a specific class of QED diagrams are obtained explicitly up to the tenth order of the electromagnetic coupling constant. Calculations are performed within the Mellin-Barnes integral representation, which is widely used in consideration of multi-loop diagrams. The corresponding...
An unexpectedly large double-spin correlation $A_{NN}$ was found at large angles in elastic pp scattering ($θ_{c.m.} = 90^◦$ ) at $\sqrt{s_{NN}} = 3$ GeV and 5 GeV in Ref. [1]. These energies correspond to the thresholds for strangeness and charm production in pp collisions, respectively. The observed strong correlations (cross-section ratio of 4 : 1 for parallel and antiparallel spins of...
One of the main goal of MPD/NICA scientific program is the precise measurement of light hadron spectra. In this report, the MPD performance to measure pt spectra of identified light hadrons at $\sqrt{s_{NN}} = 9.2$ GeV is presented as well as the performance to measure pt-integrated rapidity density dN/dy and full yields of light hadrons.
We report on newest results in kt-factorization 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...
Recently the BM@N Collaboration [1] measured the missing momentum and residual nucleus momentum distributions in proton knock-out reactions $^{12}\mbox{C}(p,2pn_s)^{10}\mbox{B}$ and $^{12}\mbox{C}(p,2pp_s)^{10}\mbox{Be}$ in the inverse kinematics with incident $^{12}\mbox{C}$ beam at 48 GeV/c on proton target. Here, "s" stands for an unobserved spectator (or recoil) nucleon. The missing...
Using first-principle numerical lattice simulations, we demonstrate that the hot gluon plasma develops strong inhomogeneity with angular rotation. In certain conditions the existence of mixed confinement-deconfinement phase, when the periphery and central regions of rotating system are in the different phases, becomes possible. We study the spatial distribution of the Polyakov loop in the...
We have derived the exact and approximate transverse momentum distributions for the Bose-Einstein, Fermi-Dirac and Maxwell-Boltzmann statistics of particles in the Tsallis statistics with escort probabilities (the Tsallis-3 statistics). The Tsallis-3 statistics is considered by the scientific community to be the most correct. We have found that the classical phenomenological Tsallis...
Particles produced in noncentral heavy-ion collisions are mostly twisted (vortex). They are created in electromagnetic and strong interactions. Particles emitted in strong interactions are twisted if initial interacting partons are in twisted states and are untwisted in the opposite case. A vorticity of nuclear matter plays an important role for the production of twisted particles.
The spectroscopy of charmonium-like mesons with masses above the 2_mD open charm threshold has been full of surprises and remains poorly understood. The currently most compelling theoretical descriptions of the mysterious XYZ mesons attribute them to hybrid structure with a tightly bound diquark or tetraquark core that strongly couples to S-wave DD\bar molecular like structures. The production...
We test the parametrizations of Fragmentation Functions (FFs) using data on semi-inclusive pion and kaon production in unpolarized pp and heavy-ion collisions at the STAR and NICA kinematics. The calculations are carried out in the next-to-leading order (NLO) of perturbative quantum chromodynamics (pQCD).
We show that at the c.m. energy 200 GeV both LSS-15 and DSEHS-14 FFs for pions and...
Progress in applying the Bethe-Salpeter equation to study relativistic two-particle systems, in particular the deuteron at high energies [1] as well as recent successes in the application of the Bethe-Salpeter-Faddeev formalism for the study of three-nucleon nuclei (helion and triton) (binding energy, state amplitudes and electromagnetic form factors)[2] give a reason to assume that...
Energy levels of three-particle bound systems composed
of a helium nucleus, electron in 1S ground state and Pi^-, K^- mesons
in Rydberg state with principal and orbital momentum quantum
numbers of n\sim l+1\sim 17 are studied in variational approach
in quantum electrodynamics. Vacuum polarization and relativistic
corrections are taken into account.
The technique of correlation femtoscopy helps one not only to estimate the geometric dimensions and lifetime of the particle emission region in nucleus-nucleus collisions, but also help to answer the question of whether the source has a boost-invariant spatiotemporal structure. This work is aimed to studying the femtoscopic parameters of identical-pion emission region in Au+Au collisions at...
The hadronic contribution of light-by-light scattering to the hyperfine structure of muonium is calculated using experimental data on the transition form factors of two photons into a hadron. The amplitudes of interaction between a muon and an electron with horizontal and vertical exchanges are constructed. The contributions due to the exchange of pseudoscalar, axial vector, scalar and tensor...
Two-pion interferometry provides access to the spatial and temporal size, shape and evolution of their sources created in heavy ion collisions and hence offers strong constraints for the theoretical models.
In this work, we will report the measurement of correlation strength ($\lambda$) and femtoscopic radii ($R_{\mathrm{out}}$, $R_{\mathrm{side}}$, $R_{\mathrm{long}}$,...
CALIBRATION METHODS FOR HALF-SECTORS OF THE MPD/NICA ELECTROMAGNETIC CALORIMETER ON COSMIC RAY MUONS
M.Bhattacharjee(1,3), V.M.Baryshnikov(1),P.A.Bakhtin(5),S.A.Bulychjov(2), B.Dabrowska(1,4), G.E.Fomenko(5), Yu.F.Krechetov(1), V.V. Kulikov(2), M.A. Martemianov(2), M.A. Matsyuk(2), A.Yu.Semenov(1), I.A. Tyapkin(1)
1 Joint Institute for Nuclear Research, Dubna, 141980 Russia
2 National...
The Standard Model predicts a rapid enhancement of the cross section for scattering of electron antineutrinos on electrons at energies around the $W$ boson production threshold. This enhancement, usually referred to as the Glashow resonance, is currently searched for at the IceCube Neutrino Observatory and its discovery would be a crucial test of the lepton sector of the Standard Model. We...
Femtoscopy is a primary tool for measuring the spatiotemporal characteristics of small and short-lived systems created in particle or nuclear collisions with an accuracy of 1 fm. The possibility of such measurements is due to the effects of quantum statistics and final state interactions which create the momentum correlations of two or more particles at small relative momenta in their...
The detector for adjusting the convergence of beams at the point of interaction of the MPD (Multi-Purpose Detector) installation at the NICA collider (Nuclotron-based Ion Collider fAcility) is discussed. Simulation of the detector operation for Au+Au collisions at √(S_NN )=11 ГэВ is calculated. It is shown that background events from scattering on residual gas give a negligible contribution to...
As a result of the collision of heavy ions, matter with extremely high acceleration is formed. We show that at such high accelerations, a new quantum phase transition occurs in the medium when its temperature drops below the Unruh temperature. The connection with the behavior of wave modes at the Rindler horizon and the phenomenological implications for hadronization and fast thermalization...
The Geant4 FTF model is one of two hadronic models applied in the Geant4 package [1] for simulations of particle’s and nuclei interactions with matter. It is used in many practical applications. Thus, it is very important to tune the model parameters to reproduce known experimental data. In the last decade, a large amount of experimental data on proton-proton (pp), proton-nucleus (pA) and...
This report is dedicated to multiparticle production in lepton and hadron interactions, in particularly, the region of high multiplicity.
Our gluon dominance model allows us to describe multiplicity distributions in these processes. This model includes two stages: partonic and hadronization. It confirms the active role of gluons in multiparticle production. predicts a few collective...
Global hyperon polarization and anisotropic transverse flow are important observables for studying the properties of the strongly interacting matter produced in relativistic heavy ion collisions. The former provides information about the initial angular momentum in the non-central collisions and the latter contains the information about the early evolution of the overlap region and the...
We discuss a few approaches in energy calibration of Forward Hadron Calorimeters (FHCal) at MPD with cosmic muons. A few types of muon tracks in FHCal modules were considered. The straightforward method is the selection of horizontal muons that are parallel to the longitudinal axis of calorimeter modules. In this case the energy deposition in each longitudinal sections of FHCal module is about...
The absence of really new physics demonstrates that the Nature has put screen to the ''large sledgehammer'' ( LHC) and one can conclude that to put experiment at the forefront in definite sense is similar ''to look for lost keys under lantern because it is more lightly at this place .'' Really, the Nature does not operate with lines, clocks, accelerators and uncountable set of other...
There are some indications on the existence of two barion states, that are systems with barion
number 2(dibarion) and excitation energy lower than π0 mass. Such state according to barion
number conservation after its production decays into proton and neutron and has a mass MX =
Md + Eexc,where Md and Eexc are deuteron mass and excitation energy.
The simulations of dd collisions is...
The Time Over Threshold (TOT) method using a pulse shaper based on the mathematical function of the raised cosine (FPC) is described. FPC has an important property for this method – the formation of a smooth pulse, with the variability of the smoothing coefficient and response time. At the same time, the shape of the FPC pulse does not depend on the input pulse waveform in a given time range....
The phenomenon of locking of color quarks Nc=3 in the proton-neutron - in hadrons- and the existence of three quark-lepton generations Ng=3 open the way to expanding the foundations of quantum physics itself. In this report, we will discuss a generalization of the unitarity condition with possible practical applications.
The HGN (High Granular Neutron) detector is being developed for the BM@N (Barionic Matter at Nuclotron) experiment on the extracted beam line of the Nuclotron (JINR, Dubna) to measure the azimuthal flows of neutrons with energy range 400 - 4000 MeV produced in heavy-ion collisions at the beam energies 2 – 4 AGeV. This data together with data of azimuthal flows of charged particles, which will...
Field-theoretical approach of the vector meson resonance production in reaction
$A+B\Longrightarrow V+X\Longrightarrow 1+2+X$ is applied to the
determination of location of the $V$-meson spin quantization axis.
In this approach amplitude of the reaction $A+B\Longrightarrow 1+2+X$ is
a product of the on shell and off shell amplitudes of
the subreactions $A+B\Longrightarrow...
A new high-granular neutron detector is under development for the BM@N experiment, JINR, Dubna, Russia. Its task is to measure the anisotropic collective neutron flow in the energy range of 1-4 AGeV. This measurement is crucial for studying the symmetry energy term in the equation of state of strongly interacting hadronic matter. The detector is designed with a high-granular structure,...
The report describes the new drift cameras developed for the ALPOM-2 experiment, their main characteristics and methods of operation.
The paper also describes the experience of working with ASD-8 chip, modernization of boards containing it, which allows to avoid problems with noise and to abandon obsolete preamplifiers.
A novel method of deuteron spin-flipping by the spin resonance crossing due to the betatron tunes shift is proposed. The resonance is induced by Nuclotron corrective quadrupoles, which allow one to control the resonance detuning and its strength simultaneously. Spin-flipping of deuterons is provided by adiabatic crossing of the induced resonance due to a slow change of the vertical betatron...
We present some results of analysis of hadron production in $pp$ and $AA$ collisions obtained in the framework of $z$-scaling and discuss a possible signatures of a phase transition in nuclear matter. This approach allows to systematically analyze experimental data on inclusive cross sections over a wide range of the collision energies, multiplicity densities, transverse momenta, and angles...
Nucleosynthesis at large magnetic induction relevant for core-collapse supernovae, and neutron star mergers is considered. For respective magnetic fields of a strength up to ten teratesla atomic nuclei exhibit linear magnetic response due to the Zeeman effect. Such nuclear reactivity can be described in terms of magnetic susceptibility [1]. Susceptibility maxima correspond to half-filled...
The results of an analysis of the invariant mass spectra of photon pairs produced in dC, pC
and dCu interactions at momenta of 2.75, 5.5 and 3.83 GeV/c per nucleon respectively, are
presented. Signals in the form of enhanced structures at invariant masses of about 17 and
38 MeV/c2 are observed. The results of testing of the observed signals, including the results
of the Monte Carlo...
We develop a theoretical description of the production of pions and protons in a new cumulative region of central rapidities and large transverse momenta that can be observed in nuclear collisions by the MPD and SPD detectors of the NICA complex.We suppose that particles in this kinematic region, inaccessible for single nucleon-nucleon interactions, are formed as a result of scattering from...
We discuss some new results in envisaged LUXE
experiment aims at studying strong-field QED
in electron-laser and photon-laser interactions, with
the 16.5 GeV electron beam of the European XFEL
and a laser beam with power of up to 350 TW.
We show some results for the non-linear Breit-Wheeler and Compton
processes. In particularly, we show prediction for electron-positron
production...
Characteristics of two forms of the electron-hole (eh) plasma radiation, excited in the graphene under the action of an external time dependent electric field, namely, the quasiclassical radiation of plasma waves and the quantum photon emission in the annihilation channel of interaction of the eh-plasma with a quantized electromagnetic field, are investigated and compared among themselves by...
A.T. D’yachenko$^{1,2}$
$^1$ Emperor Alexander I Petersburg State Transport University, St. Petersburg, 190031, Russia;
$^2$ B.P. Konstantinov Petersburg Nuclear Physics Institute National Research Center “Kurchatov Institute”, Gatchina, 188300, Russia
E-mail: dyachenko_a@mail.ru;
In the development of the nonequilibrium hydrodynamic approach [1, 2], we managed to completely...
The reactions $np \rightarrow np \pi^+ \pi^-$ was studied at the momenta of incident
neutrons $P_0$=3.83 and 5.20 GeV/c. There were calculated the contributions of various
diagrams (both of one-baryon and one-pion exchages) into the cross-section at the
momenta from the threshold up to 12 GeV/c. It was shown that the main contributions into
the reaction $np \rightarrow np \pi^+ \pi^-$ at...
Negative binomial distribution for semi-inclusive distributions gives Hagedorn-Tsallis distribution for inclusive distributions. Radiating sourses counting rule in the hadronization phase, confining and statistical potentials for quarkonium systems in heavy ion scettering processies considered.
Starting with the discovery of the nuclear component of cosmic rays, the nuclear track emulsion method (NTE) makes an opportunity to study the composition of the relativistic fragmentation of nuclei at high-energy accelerators. The promising potential of the relativistic approach to the analysis of ensembles of fragments was manifested in NTE exposed by nuclei at several GeV per nucleon...
One-loop electroweak radiative corrections to dilepton production in hadron collisions via photon fusion for Large Hadron Collider (LHC) experimental program are estimated, the most attention is paid to hard bremstrahlung. Discussed reaction follows the Drell-Yan process, its studying is the actual task of LHC experimental program. Detailed numerical analysis of electroweak radiative effects...
The report presents an overview of the results of the study of experimental regularities in the production of cumulative (subthreshold) particles. The spin observed in the reaction of fragmentation of polarized deuterons into cumulative hadrons (protons and pions) are discussed. Possible measurements with a new (created at JINR) source of polarized deuterons are discussed.
Studies of superconducting properties of high-temperature conductors by
methods of nuclear spectroscopy at the accelerator the NICA complex .
Tyutyunnikov S.I., Belov O.V., Novikov M.S., Stegailov V.I. ,
Vaganov Yu.A.,,Drnoyan D.R.
...
In SU(4) linear - sigma model, the quark-hadron phase structure is analyzed, at vanishing and finite temperatures. The masses of pseudoscalar, scalar, vector and axial-vector charmed meson states are determined and compared with the available lattice QCD hadron spectrocopy and particle data group. The mass modification of the charmed mesons in thermal medium could be predicted, from which the...
