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V. A. Nikitin

Publications and source records attributed to V. A. Nikitin.

8 recordsLinked to original sources
arXiv2026

Gluon dominance model and multiparticle production

The gluon dominance model describes multiparticle production of secondary particles at high energies in lepton and hadron interactions, including annihilation processes and heavy quarkonium decays. According to this model, the multiparticle process is divided into two stages. The first stage describes the development of a quark-gluon cascade as a Markov branching process in the region of perturbation QCD. For the second stage, the transformation of quarks and gluons into observable hadrons (hadronization), a phenomenological scheme is proposed. It is universal and based on an experiment. The gluon dominance model demonstrates good agreement with data over a wide energy region. It testifies that in hadron interactions valence quarks remain in the leading particles, and gluons are the sources of secondary hadrons. Quantitative estimates of the model parameters confirm the fragmentation mechanism of hadronization in leptonic interactions and the recombination mechanism in hadronic ones. The model description of the experimental distributions on the number of neutral pions in proton interactions at 50 GeV beams in the high multiplicity region are presented for the first time. It is shown that the main contribution to this region is made by gluon fission. These results can be useful in planning of future experiments.

hep-ex↗
arXiv2024

Search for a new charged particle in the mass range of 2-100 MeV

In the theory of electroweak interactions, there is no prohibition on the existence of particles with a mass other than that of an electron, muon and tauon. The task is to search for a new particle in the mass range of 2-100 MeV. The search was performed using the photo material of the 2-m propane bubble chamber. The chamber has been exposed in a 10 GeV proton beam at the JINR Synchrophasotron. For its search, ~55 thousand stereo photos have been scanned. The events of the $γ$ quantum conversion into a pair of charged particles have been analyzed. 50 anomalous events have been found in which one particle of the pair stops in the volume of the chamber, has an increased track density at the end of the range and, upon identification, detects a mass of ~ 8 MeV. The average value of the mass of the new particle is (8.5 $\pm$ 2.5) MeV

nucl-ex↗
arXiv2021

Possible studies at the first stage of the NICA collider operation with polarized and unpolarized proton and deuteron beams

This paper contains suggestions for experiments with usage of the Spin Physics Detector (SPD) at the first stage of the SPD NICA Programme developing at JINR. Double polarized pp-, dd- and pd- collisions at c.m.s. NN energies of 3.4-10 GeV, which will be accessible at the initial stage of experiments, allow one to study spin dependence of the NN interaction, search for multiquark states at double strangeness, charm and beauty thresholds, study the short-range structure of the deuteron. Double polarized pd scattering offer a possibility to test the Standard Model through the search for T-invariance violation.

hep-ph↗
arXiv2011

Neutral pion number fluctuations at high multiplicity in pp-interactions at 50 GeV

Neutral pion number N0 distributions for each total number of particles in event Ntot=Nch+N0 are obtained. The scaled variance of neutral pion fluctuations, omega=D/ , is measured. The fluctuations increase at Ntot >22. According to quantum statistics models it may indicate for the approaching to pion condensate conditions for high pion multiplicity in the system.

hep-ex↗
arXiv2011

Proton interactions with high multiplicity

Project Thermalization (Experiment SERP-E-190 at IHEP) is aimed to study the proton - proton interactions at 50 GeV with large number of secondary particles. In this report the experimentally measured topological cross sections are presented taking into account the detector response and procession efficiency. These data are in good agreement with gluon dominance model. The comparison with other models is also made and shows no essential discrepancies.

hep-ex↗
arXiv2005

Study of multiparticle production by gluon dominance model (Part II)

The gluon dominance model presents a description of multiparticle production in proton-proton collisions and proton-antiproton annihilation. The collective behavior of secondary particles in $pp$-interactions at 70 GeV/c and higher is studied in the project {\bf "Thermalization"}. The obtained neutral and charged multiplicity distribution parameters explain some RHIC-data. The gluon dominance model is modified by the inclusion of intermediate quark topology for the multiplicity distribution description in the pure $p\bar p$-annihilation at few tens GeV/c and explains behavior of the second correlative moment. This article proposes a mechanism of the soft photon production as a sign of hadronization. Excess of soft photons allows one to estimate the emission region size.

hep-ph↗
arXiv2005

Study of multiparticle production by Gluon Dominance Model

The gluon dominance model offers a description of multiparticle production in e^+e- - annihilation and proton-proton collisions. The multiplicity distributions in e^+e^- annihilation are well described. The energy dependence of model parameters gives the dynamic parton stage and hadronisation picture. It is shown that this model has confirmed oscillations in sign of the ratio of factorial cumulant moments over factorial moments of the increasing order. The collective behavior of secondary particles in $pp$-interactions at 70 GeV/c is studied in the project "Thermalization". An active role of gluons is shown in the multiparticle dynamics. This paper gives a simple thermodynamic interpretation of interactions mentioned above.

hep-ph↗