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

Jun 3, 2020, 12:45 PM


Oral Presentation Heavy Flavor and Quarkonia Parallel


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


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.

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

Primary author

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

Presentation materials