arXiv subjects

Xu-Hong Zhang

Publications and source records attributed to Xu-Hong Zhang.

5 recordsLinked to original sources

arXiv2023

Thermodynamic and hydrodynamic characteristics of interacting system formed in relativistic heavy ion collisions

To study the energy-dependent characteristics of thermodynamic and hydrodynamic parameters, based on the framework of a multi-source thermal model, we analyze the soft transverse momentum ($p_{T}$) spectra of the charged particles ($π^{-}$, $π^{+}$, $K^{-}$, $K^{+}$, $\bar{p}$, and $p$) produced in gold-gold (Au-Au) collisions at the center-of-mass energies $\sqrt{s_{NN}}=7.7$, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV from the STAR Collaboration and in lead-lead (Pb-Pb) collisions at $\sqrt{s_{NN}}=2.76$ and 5.02 TeV from the ALICE Collaboration. In the rest framework of emission source, the probability density function obeyed by meson momenta satisfies the Bose-Einstein distribution, and that obeyed by baryon momenta satisfies the Fermi-Dirac distribution. To simulate the $p_{T}$ of the charged particles, the kinetic freeze-out temperature $T$ and transverse expansion velocity $β_{T}$ of emission source are introduced into the relativistic ideal gas model. Our results, based on the Monte Carlo method for numerical calculation, show a good agreement with the experimental data. The excitation functions of thermodynamic parameter $T$ and hydrodynamic parameter $β_{T}$ are then obtained from the analyses, which shows an increase tendency from 7.7 GeV to 5.02 TeV in collisions with different centralities.

hep-ph↗

arXiv2022

Random statistical analysis of transverse momentum spectra of strange particles and dependence of related parameters on centrality in high energy collisions at the LHC

We have studied the transverse momentum ($p_T$) spectra of the final-state strange particles, including $K^{\pm}$, $ϕ$, $\itΞ$, and $\itΩ$, produced in high energy lead-lead (Pb-Pb), proton-lead ($p$-Pb), xenon-xenon (Xe-Xe) collisions at the Large Hadron Collider (LHC). Taking into account the contribution of multi-quark composition, whose probability density distribution is described by the modified Tsallis-Pareto-type function, we simulate the $p_T$ spectra of the final-state strange particles by a Monte Carlo method, which is shown to be in good agreement with the experimental data in most the cases. The kinetic freeze-out parameters are obtained. The present method provides a new tool for studying the spectra of various particles produced in high energy collisions, reflecting more realistically the collision process, which is of great significance to study the formation and properties of the produced particles.

hep-ph↗

arXiv2022

Thermal freeze-out parameters and pseudo-entropy from charged hadron spectra in high energy collisions

We collected the transverse momentum (mass) spectra of charged hadrons ($π^{-}$, $π^{+}$, $K^{-}$, $K^{+}$, $\overline{p}$, and $p$) produced in collisions over a center-of-mass energy range from 2.70 to 200 GeV (per nucleon pair). The modified Tsallis--Pareto-type function (the TP-like function) with average transverse flow velocity is used to describe the contribution of participant or constituent quarks to transverse momentum of considered hadron. The experimental spectra of $π^{\mp}$ and $K^{\mp}$ (or $\overline{p}$ and $p$) are fitted by the convolution of two (or three) TP-like functions due to the fact that two (or three) constituent quarks are regarded as two (or three) energy resources in the formation of considered hadron. From the reasonable fits to the spectra, the thermal freeze-out parameters are extracted, and the pseudo-entropy is newly defined and extracted. Some parameters quickly change in the energy range of less than 7.7 GeV, and slowly change in the energy range of greater than 7.7 GeV, indicating the variation of collision mechanism at around 7.7 GeV.

hep-ph↗

arXiv2021

A systematic analysis of transverse momentum spectra of $J/ψ$ mesons in high energy collisions

We aggregate the transverse momentum spectra of $J/ψ$ mesons produced in high energy gold-gold (Au-Au), deuteron-gold ($d$-Au), lead-lead (Pb-Pb), proton-lead ($p$-Pb), and proton-(anti)proton ($p$-$p(\overline{p})$) collisions measured by several collaborations at the Relativistic Heavy Ion collider (RHIC), the Tevatron Proton-Antiproton Collider, and the Large Hadron Collider (LHC). The collision energy (the center-of-mass energy) gets involved in a large range from dozens of GeV to 13 TeV (the top LHC energy). We consider two participant or contributor partons, a charm quark and an anti-charm quark, in the production of $J/ψ$. The probability density of each quark is described by means of the modified Tsallis--Pareto-type function (the TP-like function) while considering that both quarks make suitable contributions to the $J/ψ$ transverse momentum spectrum. Therefore, the convolution of two TP-like functions is applied to represent the $J/ψ$ spectrum. We adopt the mentioned convolution function to fit the experimental data and find out the trends of the power exponent, effective temperature, and of the revised index with changing the centrality, rapidity, and collision energy. Beyond that, we capture the characteristic of $J/ψ$ spectrum, which is of great significance to better understand the production mechanism of $J/ψ$ in high energy collisions.

hep-ph↗

arXiv2021

Statistical Behavior of Lepton Pair Spectrum in Drell-Yan Process and Signal from Quark-Gluon Plasma in High Energy Collisions

We analyze the transverse momentum ($p_{T}$) spectra of lepton pairs ($\ell\bar \ell$) generated in the Drell-Yan process, as detected in proton-nucleus (pion-nucleus) and proton-(anti)proton collisions by ten collaborations over a center-of-mass energy ($\sqrt{s_{NN}}$ or $\sqrt{s}$ if in a simplified form) range from $\sim20$ GeV to above 10 TeV. Three types of probability density functions (the convolution of two Lévy-Tsallis functions, the two-component Erlang distribution, and the convolution of two Hagedorn functions) are utilized to fit and analyze the $p_{T}$ spectra. The fit results are approximately in agreement with the collected experimental data. Consecutively, we obtained the variation law of related parameters as a function of $\sqrt{s}$ and invariant mass ($Q$). In the fit procedure, a given Lévy-Tsallis (or Hagedorn) function can be regarded as the probability density function of transverse momenta contributed by a single quark ($q$) or anti-quark ($\bar q$). The Drell-Yan process is then described by the statistical method.

hep-ph↗