报告摘要：Measurements of heavy flavor production in heavy-ion collisions have played an important role in understanding the properties of the deconfined matter, usually referred to as the quark-gluon plasma (QGP), created in such collision. Due to their large masses, heavy flavor quarks are predominately produced in hard processes at the early stage of heavy-ion collisions, which makes them well-calibrated probes whose production rate can be calculated within the framework of perturbative QCD. The energy loss and thermalization of open heavy flavor quarks in the medium, arising from their interactions with the QGP, can be studied via measurements of modifications to the open heavy flavor hadron production and its elliptic flow. On the other hand, quarkonium dissociation due to the color-screening of the quark and anti-quark potential by the surrounding partons, was proposed as a direct proof of the QGP formation. However, contributions from cold nuclear matter effects and regeneration of deconfined quark and anti-quark pairs complicate the interpretation of the experimentally observed suppression. Therefore, precision measurements of heavy flavor production in heavy-ion collisions are crucial for understanding the kinematics as well as the dynamics of the QGP. The STAR experiment at RHIC is well-equipped for measuring heavy flavor production with its large acceptance and excellent particle identification capability. In this talk, I will focus on measurements of both open heavy flavor hadrons and quarkonia, utilizing recent detector upgrades, in Au+Au collisions at center-of-mass energy of 200 GeV per nucleon pair. Specifically, the nuclear modification factor and elliptic flow for D⁰ and J/psi mesons will be shown and compared with theoretical calculations. Physics implications of these measurements will also be discussed.

报告人简介：Dr. Rongrong Ma is currently working at Brookhaven National Laboratory (BNL) as a Goldhaber fellow. He received his bachelor’s degree in physics at Peking University in 2008, and then got admitted to the graduate school at Yale University. He joined the heavy-ion group led by Prof. John Harris at Yale in 2009, and started working on jet measurements in the ALICE experiment at CERN, which in the end turned into his Ph. D. dissertation. He joined the STAR group at BNL at the beginning of 2014, and has been working there since then. His main research interest is to measure the quarkonium suppression in Au+Au collisions using the recently installed Muon Telescope Detector (MTD).

第204期“论坛”主请人联系方式：
朱相雷   62794279   zhux@tsinghua.edu.cn