$Z_c(3900)$ in a hadronic molecule and a triangle singularity approach at finite temperature

Abstract

Studying exotic hadrons is a challenge against the conventional quark model, providing us with a good platform to deepen our understanding of the strong interaction. An inclusive study of the exotic hadrons in vacuum and at finite temperature is an intriguing approach to shed light on their nature. As a first step, we study the $Z_c(3900)$ in both the $D\bar{D}^\ast$ hadronic molecular and the triangle singularity pictures, and discuss the behaviors of $Z_c(3900)$ at finite temperature in these two different pictures. As a result, we show the properties that its mass becomes smaller and its width becomes larger when the temperature increases, which are seen commonly in the hadronic molecular picture and in the triangle singularity picture. The enhanced widths in hot medium indicate that the $Z_c(3900)$ will be dissociated at a sufficiently high temperature. This feature is also reflected by a decrease of the effective couplings in the hadronic molecular picture. It is concluded that, not only in vacuum but also in hot medium, the behaviors of $Z_{c}(3900)$ are similar in the two different interpretations of $Z_c(3900)$.