Conveners
Relativistic heavy ion collisions
- Mikhail Mamaev (NRNU MEPhI)
Relativistic heavy ion collisions
- Viktor Riabov (NRC "Kurchatov Institute" PNPI)
Relativistic heavy ion collisions
- Vladimir Zherebchevsky (Saint-Petersburg State University)
Relativistic heavy ion collisions
- Nikita Bikmetov (Tomsk Polytechnic University)
Relativistic heavy ion collisions
- Vadim Dmitriev (Saratov State University)
Relativistic heavy ion collisions
- Vladimir Melezhik (BLTP JINR Dubna)
Relativistic heavy ion collisions
- Viktar Kireyeu (JINR)
Relativistic heavy ion collisions
- Vladimir Kovalenko (Saint Petersburg State University)
Hyperons created in non-central nucleus-nucleus collisions possess collective behavior known as elliptic flow (v2). Also, hyperons are sensitive to the magnetic field and vorticity of the produced system resulting in their polarization. The measurement of elliptic flow and the polarization of Lambda and Xi hyperons in Pb--Pb collisions, performed with the ALICE detector at the LHC are...
The enhancement of strangeness production has long been considered as a signature of quark–gluon plasma (QGP) formation in heavy-ion collisions. While extensive measurements have refined this idea over time, $\Sigma$ hyperons remain experimentally unexplored at the LHC energies. In this study, we present the first measurements of the transverse momentum ($p_{\mathrm{T}}$) spectra and...
The main goal in investigation of vector mesons production in
ultra-peripherall collisions (UPC) of relativistic ions is the possibility to constrain the nuclear and proton gluon distributions.
The strong electromagnetic fields accompanying heavy ions accelerated
at BNL or LHC may lead to huge vector mesons photoproduction in
ultra-peripheral collisions, where there is no overlap...
D mesons and the λ baryon are currently considered as one of the most perspective probes for search of quark de-confinement of the matter during its transition from a state of hadron gas to quark-gluon plasma. The tracking system of the MPD experiment at NICA collider will include the vertex silicon detector MPD-ITS designed for the efficient registration of these short-lived products of...
Studies of the phase diagram of strongly interacting matter created in nuclear collisions are typically carried out using event-by-event fluctuations. The strongly intensive quantities form a family of promising observables that are free from trivial volume fluctuations. In the case of multiplicity fluctuations over separate rapidity intervals, the behavior of the corresponding strongly...
In the collisions of heavy ions at the beam energy of 3.8A GeV dense baryonic matter is produced within the overlap region of colliding nuclei. The azimuthal anisotropy of produced in the collision particles is a sensitive probe of the properties of the dense baryonic environment. We present the preliminary results for the first coefficient of the Fourier decomposition of azimuthal...
The effect of nuclear medium on proton-nucleus scattering amplitude is investigated by analyzing experimental differential cross sections of proton elastic scattering on $^{90}$Zr at a very wide range of incident energies from 12.7 to 1000 MeV using the microscopic model of proton–nucleus optical potential. This effect has a major impact on the proton-nucleon cross section, σ, the most...
We investigate the transverse momentum spectra and entropy per unit rapidity of charged pions produced in central Au--Au collisions at $\sqrt{s_{NN}} = 7.7$ and $11.5$~GeV, relevant for the NICA energy domain. The low-$p_T$ region is fitted using a Tsallis distribution, while the intermediate-to-high $p_T$ tail is described by a hadron resonance gas (HRG) model incorporating resonance decay...
Direct photons produced in electromagnetic processes in heavy ion collisions do not interact with other particles in the collision zone. Analysis of direct photon spectra and anisotropic flow could provide additional information on the conditions at the production time and on the development of collective flow. Spectra and flow of direct photons are quantified based on the corresponding...
Recent results on short-lived hadronic resonances obtained with the ALICE at LHC energies are presented.
These results include masses, widths, transverse momentum spectra,
yields and the ratios of resonance yields to those of longer-lived particles, and elliptic flows.
Results will be compared with model predictions and measurements at lower energies.
A key goal of beam energy scan programs with relativistic heavy-ion collisions at √sNN=2-5 GeV is probing the high-density equation of state (EoS) and possible phase transitions in dense baryonic matter. Anisotropic flow measurements provide critical insights into these properties through the final-state charged-particle azimuthal distributions. However, for the MPD experiment at NICA...
After the discovery of the Higgs boson in the LHC experiments, measurements of its properties began. The measured mass of the Higgs boson is 125 GeV. At this mass, the probability of its decay into bb is about 58%, which means that more than half of the produced Higgs bosons decay into a pair of bb quarks. Therefore, this channel is very important for studying the properties of the Higgs...
This report presents an overview of the latest results and research methodology of the search for Higgs boson decay into Dark Matter (DM) particles, using data obtained at first (√𝑠 = 7 TeV, 8 TeV ) and second (√𝑠 = 13 TeV ) Large Hadron Collider (LCH) Runs, corresponding to a luminosity of 4.9 - 19.7 and 139 - 140 fnb-1, respectively. Results were interpreted in the context of models where...
High-order net-proton cumulants and the event volume definition in A+A collisions at NICA energies.
G. Feofilov, St. Petersburg State University, St. Petersburg, RF
E-mail: g.feofilov@spbu.ru
Thermodynamic predictions [1] have indicated that the non-Gaussian fluctuations of the event-by-event observables, such as the net electric charge, the net strangeness and the net baryon...
While elliptic flow ($v_2$) is a well-established signature of the quark-gluon plasma (QGP) in heavy-ion collisions, its observation in small collision systems remains a topic of active investigation. The LHC experiments first demonstrated the existence of $v_2$ in most central high-multiplicity collisions of p+p/Pb, which was soon complemented by the observation of collective effects in d+Au...
The study of heavy-ion collisions with intermediate energies is a key direction of the future experimental program at the NICA accelerator complex. Within the scope of the collider commissioning activities, the installation of Beam-Beam Counter (BBC) prototype (Phase 0) is planned at the SPD interaction point. To determine the preliminary operation conditions for the detector, the simulation...
The initial variant of the nonperturbative kinetic theory (NPKT) in the vacuum quark-antiquark creation in the conditions of the ultrarelativistic heavy-ion collisions was represented in a simplified semiphenomenological form as the Abelian projection of QCD, where the U(1) gauge theory with the masses and color charges of the light quarks was used for primary investigation of some features of...
At the beginning of the 21st century, a new phase state of strongly interacting matter was established, known as the quark-gluon plasma (QGP) [1]. To study the formation of the QGP in collisions of heavy nuclei, the solution of a system of equations of relativistic hydrodynamics with a specific equation of state (EoS) is typically employed. In light of difficulties for non-zero baryonic...
Nuclear fragmentation first observed in photographic emulsions exposed to cosmic rays and is now studied with greater precision using nuclear track emulsion (NTE) irradiated by relativistic muons. This approach offers a unique way to investigate multi-fragmentation processes induced purely by electromagnetic interactions [1]. Within the BECQUEREL experiment [2], we examined μ-nucleus...
In this talk we present the results of application of the Monte Carlo
modified Glauber model [1], [2], [3] for the predictions of collision centrality dependence of the total charged-particle yields for 16O +16O and 20Ne+20Ne colliding systems at the LHC.
Our model differs from the Standard Glauber model by the effective account of the energy losses in successive inelastic...
Centrality is a key parameter characterizing the geometry of relativistic heavy-ion collisions, defining the size of the interaction region and enabling comparisons with model predictions and other experimental results. The Glauber method, based on charged-particle multiplicity, is reliable at high energies but, at low energies with small multiplicities, exhibits uncertainties in impact...
A motivation for the baryon femtoscopy at the energy range of the experiment Baryonic Matter at the Nuclotron (BM@N) is discussed. The BM@M results on the proton-proton and proton-deuteron femtoscopy in the interactions of the argon beam of 3.2 AGeV kinetic energy with the C, Al, Cu, Sn, Pb targets are presented. The analysis procedure is described in detail. The dependence of the pp and pd...
A scheme for searching for anomalous leptons using a
magnetic spectrometer based on drift chambers and an electromagnetic
calorimeter is considered. The design and characteristics of the detectors are given, as well as the results of tests in cosmic rays. An estimate of the masses of the presumed
particles is given.
Charged fragment spectator yields were measured using the forward scintillation wall (ScWall) in Xe+CsI collisions at a xenon beam energy of 3.8 AGeV in the first physics run of the Baryonic Matter at Nuclotron (BM@N) experiment. The design and performance characteristics of the multichannel ScWall are presented. The yields of light charged spectator fragments produced in this reaction are...
A.T. D’yachenko$^{1,2}$
$^1$B.P. Konstantinov Petersburg Nuclear Physics Institute, National Research Center "Kurchatov Institute", Gatchina, Russia
$^2$Emperor Alexander I Petersburg State Transport University, St. Petersburg, Russia
In the BM@N collaboration experiment, double differential distributions of transverse momentum and rapidity of positively charged pions and kaons have...
The study of strange hadrons plays a critical role in understanding the properties of hot and dense
nuclear matter created in heavy-ion collisions, as they provide unique insights into the quantum chromodynamics phase transition and the possible formation of a quark-gluon plasma. Strangeness enhancement, first proposed as a signature of quark-gluon plasma, arises from the high...
In this study, we calculate the transverse momentum distributions of hadrons using two frameworks: the finite-volume blast-wave model under local equilibrium and the Tsallis-3 statistics model under global equilibrium. To implement the local equilibrium model, we analyzed the relativistic Planck and Ott transformations for thermodynamic quantities. The Planck transformations are derived from...
Collective flow measurements are essential for studying the strongly-interacting matter formed in relativistic heavy-ion collisions. Lambda hyperons serve as unique probes due to their strangeness, offering distinct sensitivity to partonic collectivity and hadronization mechanisms compared to lighter particle species. This study investigates the directed and elliptic flow of lambda hyperons in...
In relativistic heavy ion collisions, a dense hot matter called quark-gluon plasma (QGP) is formed [1]. Information about the properties of formed medium can be obtained from data on the energy loss of quarks and gluons (partons) with high transverse momenta $p_{T}≫Λ_{QCD}$ produced in hard parton-parton interactions [2]. The energy loss of partons in QGP leads to the jet quenching effect in...
Understanding the properties of Quark-Gluon Matter (QGM) at high baryon densities is essential for mapping the QCD phase diagram, probing the equation of state of dense nuclear matter, and shedding light on the structure of neutron stars and the evolution of the early universe. At high baryon potential, theoretical calculations of QCD become sophisticated and unstable. Therefore, the study of...
The research program of the SPD experiment at NICA facility is focused on studies of collisions of polarized protons and deuterons [1,2]. Studies of collisions of non-polarized light nuclei, 12C and 40Ca, are also considered as a possible extension of the SPD research program [3]. The SPD setup will be equipped with a pair of Zero Degree Calorimeters (ZDC) for luminosity measurements and...
In the year 1971 the pioneering works on fragmentation reactions in the collisions at relativistic energies began. At the same time in experiments at low energies deep- inelastic mechanism was discovered. To describe the fragmentation reactions at relativistic energies different models such as the EPAX and the Abrasion–Ablation models were developed. As the experiments on projectile...
This work focuses on the challenge of estimating multiple parameters in heavy-ion collisions using data-driven techniques [1-3]. A significant difficulty arises from the dependence of algorithm accuracy on the choice of event generator models such as QGSM [4], EPOS [5], and PHQMD [6], which introduce biases affecting parameter reconstruction.
We evaluated several approaches to mitigate...
A primary objective of relativistic heavy-ion collision beam energy scan programs is to explore the high-density equation of state (EoS) and potential phase transitions in dense baryonic matter. Anisotropic flow measurements, defined from the azimuthal distributions of final-state charged particles, offer a powerful tool to extract such information. The correlations between different flow...
A new generalization of the Multipomeron exchange model [1-4] for studying the multiparticle production in pp, pA and AA collisions is proposed, taking into account the effect of event-by-event string tension fluctuations [5]. It is shown that the new version of the model correctly reproduces the characteristic thermal behavior of $p_\rm{T}$ spectra in a wide energy range. Simultaneously, the...
An analysis of reconstructed $p_T$ spectra for light hadrons ($\pi^\pm$, $K^\pm$, $p$, $\bar{p}$) is presented for simulated Bi+Bi collisions at $\sqrt{s_{NN}} = 9.2$ GeV. The spectra are obtained with MPDRoot. The yield rapidity densities and meson yields are got. An improvement of low-$p_T$ energy loss correction is done.
We investigate the collision energy dependence of the average transverse energy < (dE_t)/(dy)> at midrapidity registered at midrapidity (|y|<0.5) for identified particles (φ , K+, K- and K mesons) produced in central Au+Au and Pb+Pb collisions over a broad energy range from RHIC to LHC (39 GeV –5020 GeV). Resonances like φ and K have different hadronic cross sections, masses and...
The formation of weakly bound clusters in the hot, dense environment at midrapidity is among the intriguing phenomena observed in heavy-ion collisions.
Three main approaches have been proposed to describe cluster formation:
- Coalescence at kinetic freeze-out.
- Continuous formation via potential interactions between nucleons.
- Deuteron production through hadronic reactions.
We...
Application of machine learning has become highly relevant for solving the problems of event reconstruction, particle identification, and impact parameter estimation [1, 2]. The present study focuses on the application of neural networks to predict the energy released in high-energy collisions of two gold nuclei (Au+Au) based on signals obtained from microchannel plate detectors. The initial...
Abstract. The production of strange Φ mesons in strong interactions is a potential signature for the formation of quark-gluon plasma (QGP) in relativistic heavy-ion collisions. Due to the Φ meson’s instability, it is identified through its decay into kaon pairs $(k^{+}k^{-})$. Since 2022, we at JINR have been conducting an intensive search for Φ mesons in heavy-ion and proton-proton...
Relativistic heavy-ion collisions provide a unique setting to investigate nuclear matter under varied temperatures and densities with various probes. Strangeness production serves as a sensitive probe into the properties of the Quark-Gluon Plasma (QGP). Measurements of femtoscopic correlations in high-energy heavy-ion collisions aim to unravel the space-time structure of the particle-emitting...
