题 目： Observation of new structures in the J/ψJ/ψ mass spectrum in pp collisions at √s = 13 TeV

报告人：易凯（南京师范大学）

时 间：2022年9月28日 下午 15:00

地点：理工楼1226

联系人：刘翔

报告摘要：

CMS experiment recently reported low-mass structures in the J/ψJ/ψ mass spectrum produced by proton-proton collisions at s = 13 TeV. Modelling signals with relativistic Breit-Wigner shapes, and under the assumption of the absence of interference between signal components, and between signal and back- ground, three structures are identified. Two structures are observed with local sig- nificances well above 5 standard deviations at masses of 6927 ± 9(stat) ± 5(syst) MeV and 6552 ± 10(stat) ± 12(syst) MeV. The first one is consistent with the pre- viously observed X(6900). Evidence for a third structure is found at a mass of 7287 ± 19(stat) ± 5(syst) MeV with a local significance of 4.1 standard deviations.

个人简介：

易凯，2004年在美国约翰霍普金斯大学获得粒子物理博士学位，先后在斯坦福大学和爱荷华大学做博士后，后在爱荷华大学任助理研究员和兼职教授。2019年回国在南京师范大学任校特聘教授，2020年被聘为清华大学访问教授。易凯现为CMS、CDF和Belle合作组成员，“清华-南师”CMS组负责人。