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P. Parfenov

Publications and source records attributed to P. Parfenov.

10 recordsLinked to original sources
arXiv2026

Reconstruction of the Impact Parameter in Nucleus-Nucleus Collisions at the MPD Experiment

Event classification by centrality is one of the key tasks of the MPD (Multi-Purpose Detector) experiment at the NICA collider. Centrality characterizes the initial geometry of heavy-ion collisions through the correlation of measured observables with the impact parameter. Typically, charged-particle multiplicity serves as the observable of choice. However, this approach can introduce autocorrelation in net-proton multiplicity fluctuation studies. In this work, we propose a novel approach based on the combined use of signals from the forward hadron calorimeter (FHCal) and the electromagnetic calorimeter (ECal). This method is expected to suppress autocorrelation in the study of proton multiplicity fluctuations, while the combination of data from both detectors will enable unambiguous centrality event classification across the full centrality range.

hep-ex↗
arXiv2025

A Two-dimensional Bayesian Approach to Centrality Determination in Nucleus-Nucleus Collisions

The determination of centrality in nucleus-nucleus collisions is a crucial task, as it enables the estimation of the impact parameter and thereby allows for the comparison of experimental results with predictions from theoretical models and other experiments. In this work, we present a two-dimensional approach for centrality determination based on a Bayesian framework. The observables used were the number of track hits and the deposited energy of spectators in the forward hadronic calorimeter. A distribution is proposed to describe the fluctuations of these two observables at a fixed impact parameter value. This distribution provides a more precise description of the observable distributions in both central and peripheral regions. The effectiveness of the proposed method was tested within a realistic BM@N simulation framework for Xe+CsI collisions at a beam energy of 3.8A GeV.

hep-ex↗
arXiv2025

Performance study of the Highly Granular Neutron Detector prototype in the BM@N experiment

The time-of-flight Highly Granular Neutron Detector (HGND) with a multilayer longitudinal structure of interleaved absorber and scintillator plates, high transverse granularity and a time resolution of about 150 ps is currently under development. The detector is designed to identify neutrons produced in nucleus-nucleus collisions and measure neutron kinetic energies of 0.3-4 GeV by the time-of-flight method in the BM@N experiment at the NICA accelerator complex at JINR. In order to validate the concept of the full-scale HGND, a compact HGND prototype was first designed and built, and its performance was studied in the BM@N experiment. The acceptance of the HGND prototype and the detection efficiency of forward neutrons emitted in hadronic fragmentation and electromagnetic dissociation (EMD) of 3.8A GeV 124Xe projectiles interacting with a CsI target were calculated by means of the DCM-QGSM-SMM and RELDIS models, respectively. The energy distributions of forward spectator neutrons and neutrons from the EMD were measured and compared with the simulations. The developed methods will be used to calibrate the full-scale HGND and to study its efficiency.

physics.ins-det↗
arXiv2024

The Highly-Granular Time-of-Flight Neutron Detector for the BM@N experiment

A new Highly-Granular time-of-flight Neutron Detector (HGND) is being developed and constructed to measure azimuthal neutron flow and neutron yields in nucleus-nucleus interactions in heavy-ion collisions with energies up to 4A GeV in the fixed target experiment BM@N at JINR. Details of the detector design and results of performance studies for neutron identification and reconstruction are shown. Comparison of simulations for different options of the HGND layout at the BM@N is presented. Several proposed methods of neutron reconstruction including machine learning and cluster methods are discussed.

hep-ex↗
arXiv2024

Performance of the Scintillation Wall in the BM@N experiment

The performance of the scintillation wall (ScWall) has been studied in the first physics run at the Baryonic Matter at Nuclotron (BM@N) in Xe+CsI reaction at a xenon beam energy of 3.8 and 3.0 AGeV. The design and functionality of the ScWall emphasizing its ability to detect charged spectator fragments produced in nucleus-nucleus interactions are shown. The simulation results regarding ScWall's capability to determine collision geometry and the comparison between measured and simulated charged spectators fragments spectra are discussed.

hep-ex↗
arXiv2023

Development of High Granular Neutron Time-of-Flight Detector for the BM@N experiment

The HGND (High Granular Neutron Detector) is developed for the BM@N (Baryonic Matter at Nuclotron) experiment on the extracted beam of the Nuclotron at JINR, Dubna. The HGND will be used to measure the azimuthal flow of neutrons produced with energies ranging from 300 to 4000 MeV in heavy-ion collisions at beam energies of 2--4 AGeV. The azimuthal flow of charged particles will be measured using the BM@N magnet spectrometer. The data on the azimuthal flow of neutrons will shed light on the study of the high-density Equation of State (EoS) of isospin-symmetric nuclear matter, which is crucial for studying astrophysical phenomena such as neutron stars and their mergers. The HGND has a highly granular structure with approximately 2000 plastic scintillation detectors (cells), each measuring 4$\times$4$\times$2.5 cm$^3$. These detectors are arranged in 16 layers, with 121 detectors in each layer, and are subdivided by copper absorber plates with a thickness of 3 cm. The light from each cell is detected with SiPM (Silicon Photomultiplier) with an active area of 6$\times$6 mm$^2$. Developed multi-channel TDC board based on the Kintex FPGA chip with a bin width of 100 ps will be used to perform precise timestamp and amplitude measurement using Time-over-Threshold (ToT) method. Good spatial resolution due to the high granularity together with a cell's time resolution of 100-150 ps ensures neutron reconstruction with good energy resolution. The design of the detector as well as the results from test measurements and simulations have been presented.

hep-ex↗
arXiv2020

Elliptic ($v_2$) and triangular ($v_3$) anisotropic flow of identified hadrons from the STAR Beam EnergyScan program

Elliptic ($v_2$) and triangular ($v_3$) anisotropic flow coefficients for inclusive and identified charged hadrons (~$\pi^\pm$, $K^\pm$, $p$, $\bar{p}$~) at midrapidity in Au+Au collisions, measured by the STAR experiment in the Beam Energy Scan (BES) at the Relativistic Heavy Ion Collider at $\sqrt{s_{NN}}$ = $11.5$ - $62.4$ GeV, are presented. We observe that the triangular flow signal ($v_3$) of identified hadrons exhibits similar trends as first observed for $v_2$ in Au+Au collisions, i.e. (i) mass ordering at low transverse momenta, $p_T < 2$ GeV/c, (ii) meson/baryon splitting at intermediate $p_T$, $2< p_T < 4$ GeV/c, and (iii) difference in flow signal of protons and antiprotons. New measurements of $v_3$ excitation function could serve as constraints to test different models and to aid new information about the temperature dependence of the transport properties of the strongly interacting matter.

hep-ex↗
arXiv2017

Performance of the MPD experiment for the anisotropic flow measurement

The main goal of the future MPD experiment at NICA is to explore the QCD phase diagram in the region of highly compressed and hot baryonic matter in the energy range corresponding to the highest chemical potential. Properties of such dense matter can be studied using azimuthal anisotropy which is categorized by the Fourier coefficients of the azimuthal distribution decomposition. Performance of the detector response based on simulations with realistic reconstruction procedure is presented for centrality determination, reaction plane estimation, directed and elliptic flow coefficients.

hep-ex↗