# 10th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions

May 31, 2020 to June 5, 2020
Online
US/Central timezone

## Evidence of X(3872) production in PbPb collisions with CMS experiment

Jun 3, 2020, 12:45 PM
20m
https://cern.zoom.us/j/97206647749

#### https://cern.zoom.us/j/97206647749

Oral Presentation Heavy Flavor and Quarkonia

### Speaker

Jing Wang (Massachusetts Inst. of Technology (US))

### Description

The structure of the exotic meson $\chi_{c1}(3872)$, also known as $X(3872)$, is still under debate. The similarity of the $\chi_{c1}(3872)$ mass and the $D-\bar{D}^{*}$ mass threshold inspired the interpretation that $\chi_{c1}(3872)$ is a $D-\bar{D}^{*}$ “molecule” with small binding energy. Another explanation is that this meson is a tetra-quark, consisting of a di-quark and di-antiquark. Relativistic heavy-ion collisions produce an extremely hot and strongly interacting medium, which provides a new environment in which to study the nature of multi-quark states. Because of the dramatically different radii of a $D-\bar{D}^{*}$ “molecule” and a tetra-quark, the interactions of these two proposed states are expected to interact differently with the medium. Therefore, the yield of $\chi_{c1}(3872)$ in heavy-ion collisions can provide insight into its structure. The ratios of production cross-section of fully reconstructed $\chi_{c1}(3872)$ over $\psi(2S)$ in PbPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV with the CMS detector are presented.

Collaboration (if applicable) CMS Contributed Talk Heavy Flavor and Quarkonia

### Primary author

Serguei Petrushanko (M.V. Lomonosov Moscow State University (RU))

### Presentation materials

 20200603_X3872_HP2020_JingWang_v7.pdf Recording