RHIC能区重味强子的实验测量

Heavy flavor hadron measurement at RHIC

本文通过介绍重味强子与重味衰变电子的核修正因子与椭圆流的实验测量,总结与回顾了近年来高能重离子碰撞RHIC能区重味强子的实验进展.最新的测量结果表明,高横动量区D^0介子与重味衰变电子的核修正因子有显著压低,且程度与轻强子相当,说明粲夸克在碰撞产生的夸克胶子等离子体介质中有强耦合并且损失能量;同时测到了显著的D^0介子椭圆流与重味衰变电子的椭圆流,且其数值与轻强子相当,符合流体动力学特征.这两个实验证据都说明了粲夸克与碰撞产生的核介质有很强的相互作用.通过实验与模型的比较定量提取了粲夸克扩散系数等核物质的关键特征参数.

This paper reviews recent progress of the heavy flavor hadron production measurement at RHIC energy in heavy-ion collisions.Experimental results of the nuclear modification factor and elliptic flow of heavy flavor hadrons and electrons from heavy flavor decays are reported.Significant suppressions of the nuclear modification factors of D0 meson and heavy flavor decay electron at high transverse momentum,similar as light hadrons,have been observed,which indicates significant energy loss of charm quark in the Quark-Gluon Plasma created in the heavy-ion collisions.In the mean time,the elliptic flows of D0 meson and heavy flavor decay electron have been observed,and also similar as light hadrons,consisting with hydrodynamics.Above two evidences indicate strong interactions between charm quark and the nuclear medium created in the collisions.Comparison between data and models provides constraints on the key parameters of the QCD matter,such as the charm quark diffusion coefficient.