Hadronic medium effects on $Z_{cs} (3985)^-$ production in heavy-ion collisions

TL;DR

This paper investigates how the hot hadron gas environment affects the production and annihilation of the exotic multiquark state $Z_{cs}(3985)^-$ in heavy-ion collisions, using an effective Lagrangian approach.

Contribution

It provides the first estimation of thermal cross sections for $Z_{cs}$ production and annihilation processes in a hot hadron gas, highlighting the dominance of annihilation.

Findings

Thermal cross sections for $Z_{cs}$ annihilation are significantly larger than production.

The processes have sizeable cross sections, potentially impacting $Z_{cs}$ yields in heavy-ion collisions.

Results suggest $Z_{cs}$ multiplicity could be affected by medium effects.

Abstract

In this work we study the interactions of the multiquark state $Z_{cs} (3985)^-$ with light mesons in a hot hadron gas. Using an Effective Lagrangian framework, we estimate the vacuum cross sections as well as the thermal cross sections of the production processes $ \bar{D}_{s}^{(*)} D_{s}^{(*)} \rightarrow Z_{cs}^- X \, (X=\pi , K, \eta) $ and the corresponding inverse reactions. The results indicate that the considered processes have sizeable cross sections. Most importantly, the thermal cross sections for $Z_{cs}$ annihilation are much larger than those for production. This feature might produce relevant effects on some observables, such as the final $Z_{cs}$ multiplicity, measured in heavy ion collisions.