LHC/ALICE 实验底夸克产生和输运特性的研究

ALICE是TeV能量前沿下唯一致力于研究夸克物质的大型国际合作实验。在高能重离子碰撞中，重夸克产生于碰撞初期的硬散射过程，并早于夸克物质的形成时间，因此其将经历整个夸克物质的演化过程，并与夸克物质中的部分子发生相互作用，是标定夸克物质性质的优良探针。本项目将利用ALICE第二期运行中获取的高统计数据以及即将开始的第三期运行更高精度、亮度的数据，对重夸克物理开展实验研究。主要研究内容包括：非瞬时（来源于底夸克）粲介子、底介子产额核压低因子以及其集体关联的首次测量。标定底夸克在夸克物质中的空间扩散系数、热化自由度，填补实验研究的空白。

In heavy-ion collisions, heavy quarks (charm and beauty) are produced in the early state of hard scattering, due to their large mass, their formation time is shorter than the quark-gluon plasma (QGP), thus they are effective probes of the whole medium evolution. In particular, beauty quarks, being several times heavier than charm quarks, can be utilized to study the in-medium mass dependent energy loss. Moreover, beauty particles represent a cleaner probe of a strongly-coupled QGP compared to charm hadrons, in terms of the implementation of both microscopic interactions and transport, and as a measure of coupling strength without saturation due to possible thermalization. With the high precision and luminosity LHC ALICE Run2 and upcoming Run3 (2022-2024) data, this project will focus on the following topics: the nuclear suppression on the production yield and the collectivity for non-prompt charm mesons and beauty mesons, to precisely study mass dependent in-medium energy loss, the thermalization freedom and hadronization for beauty quark. Simultaneous comparison of the nuclear suppression and the collectivity with model predictions, the data will help to constraint beauty quark diffusion coefficient at the pseudocritical temperature.