Hydrodynamic description of D meson production in high-energy heavy-ion collisions  

作　　者：Chi Ding Wei-Yao Ke Long-Gang Pang Xin-Nian Wang 丁驰;柯伟尧;庞龙刚;王新年(Key Laboratory of Quark&Lepton Physics(MOE)and Institute of Particle Physics,Central China Normal University,Wuhan 430079,China;Physics Department,University of California,Berkeley,CA 94720,USA;Nuclear Science Division,Lawrence Berkeley National Laboratory,Berkeley,CA 94720,USA)

机构地区：[1]Key Laboratory of Quark&Lepton Physics(MOE)and Institute of Particle Physics,Central China Normal University,Wuhan 430079,China [2]Physics Department,University of California,Berkeley,CA 94720,USA [3]Nuclear Science Division,Lawrence Berkeley National Laboratory,Berkeley,CA 94720,USA

出　　处：《Chinese Physics C》2021年第7期205-213,共9页中国物理C（英文版）

基　　金：Supported by the National Key Research and Development Program of China (2020YFE0202002);the National Natural Science Foundation of China (11935007,11221504, 11861131009, 12075098, 11890714);the Director,Office of Energy Research,Office of High Energy and Nuclear Physics,Division of Nuclear Physics,of the U.S. Department of Energy (DOE)(DE-AC02-05CH11231);the U.S. National Science Foundation (ACI-1550228) within JETSCAPE Collaboration;(OAC-2004571) within the X-SCAPE Collaboration by the UCB-CCNU Collaboration Grant

摘　　要：The large values and constituent-quark-number scaling of the elliptic flow of low-pT D mesons imply that charm quarks,initially produced through hard processes,might be partially thermalized through strong interactions with quark-gluon plasma(QGP)in high-energy heavy-ion collisions.To quantify the degree of thermalization of low-pT charm quarks,we compare the D^(0)meson spectra and elliptic flow from a hydrodynamic model to experimental data as well as transport model simulations.We use an effective charm chemical potential at the freeze-out temperature to account for the initial charm quark production from hard processes and assume that they are thermalized in the local comoving frame of the medium before freeze-out.D^(0)mesons are sampled statistically from the freeze-out hyper-surface of the expanding QGP as described by the event-by-event(3+1)D viscous hydrodynamic model CLVisc.Both the hydrodynamic and transport models can describe the elliptic flow of D^(0)mesons at pT~3 GeV/c as measured in Au+Au collisions at√SNN=200 GeV.Though the experimental data on D^(0)spectra are consistent with the hydrodynamic result at small pT~1 GeV/c,they deviate from the hydrodynamic model at high transverse momentum,pT~2 GeV/c.The diffusion and parton energy loss mechanisms in the transport model can describe the measured spectra reasonably well within the theoretical uncertainty.Our comparative study indicates that charm quarks only approach local thermal equilibrium at small pT,even though they acquire sizable elliptic flow comparable to light-quark hadrons at both small and intermediate pT.

关 键 词：D meson relativistic hydrodynamics heavy ion collisions heavy flavor thermalization 

分 类 号：O571.6[理学—粒子物理与原子核物理]