arXiv subjects

Wenbin Zhao

Publications and source records attributed to Wenbin Zhao.

76 records · Page 5Linked to original sources

arXiv2018

Spectra and flow of light nuclei in relativistic heavy ion collisions at RHIC and the LHC

Within the framework of the coalescence model based on the phase-space distributions of protons and neutrons generated from the {\tt iEBE-VISHNU} hybrid model with {\tt AMPT} initial conditions, we study the spectra and elliptic flow of deuterons and helium-3 in relativistic heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) and the Larger Hadron Collider (LHC). Results from our model calculations for Au + Au collisions at $\sqrt{s_{NN}}=200$ GeV at RHIC and Pb+Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV at the LHC are compared with available experimental data. Good agreements are generally seen between theoretical results and experimental data, except that the calculated yield of helium-3 in Pb + Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV underestimates the data by about a factor of two. Possible reasons for these discrepancies are discussed. We also make predictions on the spectra and elliptic flow of deuterons and helium-3 in Pb + Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV that are being studied at LHC.

nucl-th↗

arXiv2018

Hydrodynamic Collectivity in Proton--Proton Collisions at 13 TeV

In this paper, we investigate the hydrodynamic collectivity in proton--proton (pp) collisions at 13 TeV, using iEBE-VISHNU hybrid model with HIJING initial conditions. With properly tuned parameters, our model simulations can remarkably describe all the measured 2-particle correlations, including integrated and differential elliptic flow coefficients for all charged and identified hadrons ($K_S^0$, $Λ$). However, our model calculations show positive 4-particle cumulant $c_{2}\{4\}$ in high multiplicity pp collisions, and can not reproduce the negative $c_{2}\{4\}$ measured in experiment. Further investigations on the HIJING initial conditions show that the fluctuations of the second order anisotropy coefficient $\varepsilon_{2}$ increases with the increase of its mean value, which leads to a similar trend of the flow fluctuations. For a simultaneous description of the 2- and 4- particle cumulants within the hydrodynamic framework, it is required to have significant improvements on initial condition for pp collisions, which is still lacking of knowledge at the moment.

nucl-th↗

arXiv2017

The global existence and large time behavior of smooth compressible fluid in an infinitely expanding ball, III: the 3-D Boltzmann equation

This paper is a continuation of the works in \cite{Euler} and \cite{NS}, where the authors have established the global existence of smooth compressible flows in infinitely expanding balls for inviscid gases and viscid gases, respectively. In this paper, we are concerned with the global existence and large time behavior of compressible Boltzmann gases in an infinitely expanding ball. Such a problem is one of the interesting models in studying the theory of global smooth solutions to multidimensional compressible gases with time dependent boundaries and vacuum states at infinite time. Due to the conservation of mass, the fluid in the expanding ball becomes rarefied and eventually tends to a vacuum state meanwhile there are no appearances of vacuum domains in any part of the expansive ball, which is easily observed in finite time. In the present paper, we will confirm this physical phenomenon for the Boltzmann equation by obtaining the exact lower and upper bound on the macroscopic density function.

math.AP↗

arXiv2017

Collective flow in 2.76 A TeV and 5.02 A TeV Pb+Pb collisions

In this paper, we study and predict flow observables in 2.76 A TeV and 5.02 A TeV Pb +Pb collisions, using the iEBE-VISHNU hybrid model with TRENto and AMPT initial conditions and with different forms of the QGP transport coefficients. With properly chosen and tuned parameter sets, our model calculations can nicely describe various flow observables in 2.76 A TeV Pb +Pb collisions, as well as the measured flow harmonics of all charged hadrons in 5.02 A TeV Pb +Pb collisions. We also predict other flow observables, including $v_n(p_T)$ of identified particles, event-by-event $v_n$ distributions, event-plane correlations, (Normalized) Symmetric Cumulants, non-linear response coefficients and $p_T$-dependent factorization ratios, in 5.02 A TeV Pb+Pb collisions. We find many of these observables remain approximately the same values as the ones in 2.76 A TeV Pb+Pb collisions. Our theoretical studies and predictions could shed light to the experimental investigations in the near future.

nucl-th↗