$X(3872)$, $X(4014)$, and their bottom partners at finite temperature

TL;DR

This paper investigates the thermal behavior of exotic charmonium-like states $X(3872)$ and $X(4014)$, predicting their mass decrease and width increase at finite temperature, with implications for heavy-ion collisions and lattice QCD.

Contribution

It dynamically generates the properties of $X(3872)$ and $X(4014)$ at finite temperature using an effective hadron theory and extends predictions to their bottom partners.

Findings

Mass decreases with temperature for all states.

Decay widths increase as temperature rises.

Predictions applicable to heavy-ion collision experiments.

Abstract

The properties of the $X(3872)$ and its spin partner, the $X(4014)$, are studied both in vacuum and at finite temperature. Using an effective hadron theory based on the hidden-gauge Lagrangian, the $X(3872)$ is dynamically generated from the $s$-wave rescattering of a pair of pseudoscalar and vector charm mesons. By incorporating the thermal spectral functions of open charm mesons, the calculation is extended to finite temperature. Similarly, the properties of the $X(4014)$ are obtained out of the scattering of charm vector mesons. By applying heavy-quark flavor symmetry, the properties of their bottom counterparts in the axial-vector and tensor channels are also predicted. All the dynamically generated states show a decreasing mass and acquire an increasing decay width with temperature, following the trend observed in their meson constituents. These results are relevant in relativistic heavy-ion collisions at high energies, in analyses of the collective medium formed after hadronization or in femtoscopic studies, and can be tested in lattice-QCD calculations exploring the melting of heavy mesons at finite temperature.