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The analysis of Pb+Pb data for net-charge fluctuations at LHC energies within the HYDJET++ model is presented. The strongly intensive quantities $D$ and $\Sigma$ are used to get rid of the effects related to volume fluctuations of the system. We employ two versions of the HYDJET++ for the analysis. The first one is the standard or default version, whereas the second one represents its further modification, which takes into account explicit event-by-event conservation of the electric net-charge of produced particles. Inclusion of the canonical net-charge conservation in the model allows one for better description of the experimental data obtained by the ALICE and the CMS Collaborations. Comparison with calculations of other models is also presented., Comment: LATEX, 8 pages, 8 figures

Data from the Large Hadron Collider on the charge balance function in Pb+Pb collisions at center-of-mass energy 2.76~TeV per nucleon pair are analyzed and interpreted within the framework of the \hydjet++ model. This model allows us to qualitatively reproduce the experimentally observed centrality dependence of the balance function widths at relatively low transverse momentum intervals due to the different charge creation mechanisms in soft and hard processes. However, a fully adequate description of the balance function in these intervals implies an essential modification of the model by including exact charge conservation via the canonical rather than the grand canonical ensemble. A procedure is proposed for introducing charge correlations into the thermal model without changing other model parameters. With increasing transverse momenta, the default model results describe the experimental data much better because the contribution of the soft component of the model is significantly reduced in these transverse momentum intervals. In practical terms, there is a transition to a single source of charge correlations, namely, charge correlations in jets in which exact charge conservation holds at each stage., Comment: Matches published version

LHC data on the correlations of the elliptic flow $v_2$ of particles at low and high transverse momenta $p_T$ from Pb+Pb collisions at center-of-mass energy per nucleon pair $\sqrt{s_{NN}} = 5.02$ TeV are analyzed in the framework of the HYDJET++ model. This model includes soft and hard components which allows to describe the region of both low and high transverse momenta. The origin of $v_2$ values in different $p_T$ regions is investigated at different centralities. It is shown that the experimentally observed correlations between $v_2$ at low and high $p_T$ in peripheral lead-lead collisions is due to correlation of particles in jets.

A simple geometrical model with event-by-event fluctuations is suggested to study elliptical and triangular eccentricities in the initial state of relativistic heavy-ion collisions. This model describes rather well the ALICE and ATLAS data for Pb+Pb collisions at center-of-mass energy $\sqrt{s_{NN}} = 5.02$~TeV per nucleon pair, assuming that the second, $v_2$, and third, $v_3$, harmonics of the anisotropic flow are simply linearly proportional to the eccentricities $\varepsilon_2$ and $\varepsilon_3$, respectively. We show that the eccentricity $\varepsilon_3$ has a pure fluctuation origin and is substantially dependent on the size of the overlap area only, while the eccentricity $\varepsilon_2$ is mainly related to the average collision geometry. Elliptic flow, therefore, is weakly dependent on the event-by-event fluctuations everywhere except of the very central collisions 0--2%, whereas triangular flow is mostly determined by the fluctuations. The scaling dependence of the magnitude of the flow harmonics on atomic number, $v_n \propto A^{-1/3}$, is predicted for this centrality interval., Comment: Further development and extension of ideas discussed in arXiv:2007.04850. Accepted for publication in J. of Physics G: Nucl. and Part. Physics

Data from the Large Hadron Collider on elliptic flow correlations at low and high $p_T$ from Pb+Pb collisions at $\sqrt{s_{NN}} = 5.02$~TeV are analyzed and interpreted in the framework of the HYDJET++ model. This model allows us to describe simultaneously the region of both low and high transverse momenta and, therefore, to reproduce the experimentally observed nontrivial centrality dependence of elliptic flow correlations. The origin of the correlations between low and high-$p_T$ flow components in peripheral lead-lead collisions is traced to correlations of particles in jets., Comment: Matches the published version

The phenomenological analysis of various characteristics of $J/\psi$ and $D$ meson production in PbPb collisions at the center-of-mass energy 2.76 TeV per nucleon pair is presented. The data on momentum spectra and elliptic flow are reproduced by two-component model HYDJET++ including thermal and non-thermal charm production mechanisms. The significant part of $D$-mesons is found to be in a kinetic equilibrium with the created medium, while $J/\psi$-mesons are characterized by earlier (as compared to light hadrons) freeze-out., Comment: 15 pages including 8 figures as EPS-files; prepared using LaTeX package for publication in the Journal of Physics G

The phenomenological analysis of the LHC data on transverse momentum spectrum and elliptic flow of $J/\psi$ and D mesons in PbPb collisions at center-of-mass energy 2.76 TeV per nucleon pair is presented. The charmed meson production pattern in PbPb collisions may be reproduced by two-component model HYDJET++ including thermal and non-thermal components. The significant part of D-mesons is found to be in a kinetic equilibrium with the created medium, while $J/\psi$-mesons are not., Comment: Talk given at 15th International Conference on Strangeness in Quark Matter (Dubna, Russia, July 6-11, 2015); 4 pages including 4 figures as EPS-files; prepared using LaTeX package for publication in Journal of Physics: Conference Series

The LHC data on azimuthal anisotropy harmonics from PbPb collisions at center-of-mass energy 2.76 TeV per nucleon pair are analyzed and interpreted in the framework of the HYDJET++ model. The cross-talk of elliptic $v_2$ and triangular $v_3$ flow in the model generates both even and odd harmonics of higher order. Comparison with the experimental data shows that this mechanism is able to reproduce the $p_{\rm T}$ and centrality dependencies of quadrangular flow $v_4$, and also the basic trends for pentagonal $v_5$ and hexagonal $v_6$ flows., Comment: 12 pages including 13 figures as EPS-files; prepared using LaTeX package for publication in the European Physical Journal C

Partial contributions of elliptic v_2 and triangular v_3 flows to the hexagonal v_6 flow are studied within the HYDJET++ model for Pb+Pb collisions at sqrt{s}=2.76 TeV. Scaling of the ratio v_6^{1/6}{Psi_2} / v_2^{1/2}{Psi_2} in the elliptic flow plane, Psi_2, is predicted in the range 1 < p_T < 4 GeV/c for semicentral and semiperipheral collisions. Jets increase this ratio by about 10% and also cause its rise at p_T > 3.5 GeV/c. The part of v_6 coming from v_2 is instantly increasing as the reaction becomes more peripheral, whereas the contribution of v_3 to v_6 drops. This behavior explains the experimentally observed increase of correlations between second and sixth harmonics and decrease of correlations between third and sixth harmonics with rising impact parameter $b$. Our study favors the idea that basic features of the hexagonal flow can be understood in terms of the interplay of elliptic and triangular flows., Comment: Final version

We estimate the amount of collective "elliptic flow" expected at mid-rapidity in proton-proton (p-p) collisions at the CERN Large Hadron Collider (LHC), assuming that any possible azimuthal anisotropy of the produced hadrons with respect to the plane of the reaction follows the same overlap-eccentricity and particle-density scalings as found in high-energy heavy ion collisions. Using a Glauber eikonal model, we compute the p-p eccentricities, transverse areas and particle-multiplicities for various phenomenological parametrisations of the proton spatial density. For realistic proton transverse profiles, we find integrated elliptic flow v2 parameters below 3% in p-p collisions at sqrt(s) = 14 TeV., Comment: 17 pages, 9 figures. Very minor mods. Version to appear in EPJ-C

The azimuthal anisotropy of charged particles in heavy ion collisions is an important probe of quark-gluon plasma evolution at early stages. In the present paper the elliptic flow pattern in Pb+Pb collisions at sqrt{s}=5.5 TeV is analyzed for different hadron species in the frameworks of HYDJET++ Monte-Carlo model. The influence of resonance decays on particle flow is investigated. The different methods of elliptic flow reconstruction are compared under LHC conditions., Comment: 10 pages, Conference: High-pT Physics at LHC -09, February 4- 7 2009, Prague, Czech Republic

The event-by-event analysis of multiparticle production in high energy hadron and nuclei collisions can be performed using the discrete wavelet transformation. The ring-like and jet-like structures in two-dimensional angular histograms are well extracted by wavelet analysis. For the first time the method is applied to the jet-like events with background simulated by event generators, which are developed to describe nucleus-nucleus collisions at LHC energies. The jet positions are located quite well by the discrete wavelet transformation of angular particle distribution even in presence of strong background., Comment: 6 pages, 6 figures