Temperature Effects on a Vector Hidden-Charm Molecule

TL;DR

This study analyzes the thermal behavior of the $Y(4500)$ molecular state using thermal QCD sum rules, revealing its significant modifications and eventual dissociation near the deconfinement temperature.

Contribution

First application of thermal QCD sum rules to the $Y(4500)$ state, providing predictions for its thermal modifications and dissociation in quark-gluon plasma.

Findings

Mass decreases by 29% near $T_c$

Decay constant suppressed by 94% at $T_c$

Decay width increases by 35% approaching $T_c$

Abstract

We investigate the thermal properties of the $Y(4500)$ state within the framework of thermal QCD sum rules, assuming a $D_s \bar{D}_{s1}$ molecular configuration with $J^{PC}=1^{--}$. The analysis is performed at both zero and finite temperatures, employing the operator product expansion up to dimension-5 condensates. The Borel window and continuum threshold are carefully selected to ensure OPE convergence and pole dominance. As the temperature approaches the deconfinement temperature $T_c$, the $Y(4500)$ undergoes significant medium modifications: its mass decreases by $29\%$ and its decay constant is suppressed by $94\%$ relative to their vacuum values, while the decay width increases by $35\%$, signaling the dissociation of the state in the medium. These results indicate that the $Y(4500)$ becomes unstable near $T_c \approx 155~\mathrm{MeV}$, consistent with its melting into the quark-gluon plasma. The obtained thermal spectral parameters may serve as signatures for identifying the $Y(4500)$ in heavy-ion experiments at RHIC and LHC, and provide predictions for sequential suppression patterns in the exotic hadron sector.