Martin Kirakosyan

This paper presents an assessment of nuclear reaction yields of protons, α-particles, and neutrons in human tissue-equivalentmaterial in proton therapy using a simulation with Geant 4. In this study, we also check an enhancement of nuclear reactions due to the presence of Bi, Au, 11B, and 10B radiosensitizer nanoparticles. We demonstrate that a proton beam induces a noticeable amount of nuclear reactions in the tissue. Nevertheless, the enhancement of nuclear reaction products due to radiosensitizer nanoparticles is found to be negligible.

The spectrum of Cherenkov gluons is calculated within the framework of in-medium QCD. It is compared with experimental data on the double-humped structure around the away-side jet obtained in the experiments STAR and PHENIX at RHIC. The values of the real and imaginary parts of the permittivity of the medium created in ultrarelativistic nuclear collisions are obtained from these fits. It is shown that accounting for an additional smearing of transverse momenta of Cherenkov gluons in the medium allows to provide a very good description of the experimental data.

The PMTs of the CMS Hadron Forward calorimeter were found to generate a large size signal when their windows were traversed by energetic charged particles. This signal, which is due to Čerenkov light production at the PMT window, could interfere with the calorimeter signal and mislead the measurements. In order to find a viable solution to this problem, the response of four different types of PMTs to muons traversing their windows at different orientations is measured at the H2 beam-line at CERN. Certain kinds of PMTs with thinner windows show significantly lower response to direct muon incidence. For the four anode PMT, a simple and powerful algorithm to identify such events and recover the PMT signal using the signals of the quadrants without window hits is also presented. For the measurement of PMT responses to Čerenkov light, the Hadron Forward calorimeter signal was mimicked by two different setups in electron beams and the PMT performances were compared with each other. Superior performance of particular PMTs was observed.

This letter is based on a kinetic theory approach to anisotropic hydrodynamics. We derive the sound wave equation in anisotropic hydrodynamics and show that a corresponding wave front is ellipsoidal. The phenomenon of Mach cone emission in anisotropic hydrodynamics is studied. It is shown that Mach cone in anisotropic case becomes asymmetric, i.e., in this limit they’re two different angles, left and right with respect to the ultrasonic particle direction, which are determined by the direction of ultrasonic particle propagation and the asymmetry coefficient.

Energy losses of fast charged particles in randomly spatially inhomogeneous stationary medium are considered. Analytical results for effective dielectric permittivity are presented.

Energy losses of fast color particles in random inhomogeneous color medium created in high energy nuclear collisions are estimated.

A short review of the two recently analyzed collective effects in dense non-Abelian matter, the photon and dilepton production in nonequilibrium glasma and polarization properties of turbulent Abelian and non-Abelian plasmas, is given.

In this proceedings contribution, we review recent calculations of the dynamics of the chromo-Weibel instability in the quark-gluon plasma.This instability is present in gauge theories which possess a one-particle distribution function which, in the local rest frame, is momentum-space anisotropic.The conditions necessary for triggering this instability can be present already in the color-glass-condensate initial state or dynamically generated by the rapid longitudinal expansion of the matter created in a heavyion collision.Using the hard-loop framework, we study the case that the one-particle distribution function possesses an arbitrary initial momentum anisotropy that increases in time due to longitudinal free streaming.The resulting three-dimensional dynamical equations for the chromofield evolution are solved numerically.We find that there is regeneration of the longitudinal pressure due to unstable plasma modes; nevertheless, the system seems to maintain a high-degree of momentum-space anisotropy.Despite this anisotropy, we find that there is rapid longitudinal thermalization of the plasma due to the non-linear mode couplings inherent in the unstable evolution.

This paper presents an overview of Monte Carlo (MC) event generators for simulation of proton-proton collisions along with the results on hadron production at nuclotron-based ion collider facility (NICA) energies. Namely, mean multiplicities, mean transverse momenta, and rapidity distributions of p(), π±, K± at different collision energies are presented. We also study two-particle angular correlations for stable charged particles. Results of simulations with PYTHIA, EPOS, SMASH, and UrQMD event generators are compared to available data. Connections of studied quantities with physics mechanisms in MC generators are discussed. We suggest a tuned set of parameters to address observed discrepancies between data and PYTHIA.

Polarization properties of turbulent stochastically inhomogeneous ultrarelativistic QED plasma are studied. It is shown that the sign of nonlinear turbulent Landau damping corresponds to an instability of the spacelike modes and, for sufficiently large turbulent fields, to an actual instability of a system.

Polarization properties of turbulent stochastically inhomogeneous ultrarelativistic QED plasma are studied. It is shown that the sign of nonlinear turbulent Landau damping corresponds to an instability of the spacelike modes and, for sufficiently large turbulent fields, to an actual instability of a system. Modification of plasmon dispersion relations due to turbulent effects are studied.

A short review of the two recently analyzed collective effects in dense non-Abelian matter, the photon and dilepton production in nonequilibrium glasma and polarization properties of turbulent Abelian and non-Abelian plasmas, is given.

Polarization properties of turbulent stochastically inhomogeneous ultrarelativistic QED plasma are studied. It is shown that the sign of nonlinear turbulent Landau damping corresponds to an instability of the spacelike modes and, for sufficiently large turbulent fields, to an actual instability of a system.

This paper presents an overview of Monte Carlo(MC) event generators for simulation of proton-proton collisions along with results on the hadron production at Nuclotron-based Ion Collider fAcility (NICA) energies. Namely, mean multiplicities, mean transverse momenta, and rapidity distributions of p($\bar{\rm p}$), $\mathrm{K}^{\pm}$, $\pi^{\pm}$ at different collision energies are presented. We also study two-particle angular correlations for stable charged particles. Results of MC simulations are compared to the available data. Connections of studied quantities and physics mechanisms in the MC models are discussed.

This paper presents an overview of Monte Carlo(MC) event generators for simulation of proton-proton collisions along with the results on hadron production at Nuclotron-based Ion Collider fAcility (NICA) energies. Namely, mean multiplicities, mean transverse momenta, and rapidity distributions of p($\bar{\rm p}$), $\pi^{\pm}$, $\mathrm{K}^{\pm}$ at different collision energies are presented. We also study two-particle angular correlations for stable charged particles. Results of simulations with \pythia, \epos, and \urqmd event generators are compared to available data. Connections of studied quantities with physics mechanisms in MC generators are discussed. We suggest a tuned set of parameters to address observed discrepancies between data and \pythia.