题 目： Evolution of charm-meson ratios and thermal energy of a charm-meson molecule in an expanding hadron gas

报告人：何丽萍  博后（波恩大学）

时 间：2023年2月17日 上午 09:30

地  点：理工楼1226

联系人：刘翔

报告摘要：

We study the time evolution of the number of charm mesons after the kinetic freeze-out of the hadron gas produced by a central heavy-ion collision. The π D* → π D* reaction rates have t-channel singularities that give contributions inversely proportional to the thermal width of the D.  The ratio of the D0 and D+ production rate can differ significantly from those predicted using the measured D* branching fractions.

We then study the thermal correction to the propagator of a loosely bound charm-meson molecule in a pion gas to next-to-leading order in the heavy-meson expansion. The correction comes primarily from the complex thermal energy shift of the charm-meson constituents. The remaining correction gives a tiny decrease in the binding energy of the molecule and a tiny change in its thermal width. These results are encouraging for the prospects of observing loosely bound charm-meson molecules in the hadron gas produced by the heavy-ion collisions.

个人简介：

何丽萍，2012年本科，2015年硕士毕业于兰州大学，2021年博士毕业于俄亥俄州立大学，2021年以来在波恩大学做博士后。主要研究三角图奇点，X(3872)等奇特强子态的产生以及其在重离子碰撞产生的强子气体中的性质及演化。