Charmonia above the Deconfinement Phase Transition

TL;DR

This study uses lattice QCD and the maximum entropy method to show that certain charmonium states remain bound in the quark-gluon plasma up to about 1.6 times the critical temperature, indicating non-perturbative effects.

Contribution

It provides the first lattice QCD evidence that $J/a$ and $b_c$ charmonia survive above the deconfinement transition, highlighting the non-perturbative nature of the plasma.

Findings

$J/\psi$ and $\eta_c$ survive up to $1.6 T_c$

Charmonia dissociate between $1.6 T_c$ and $1.9 T_c$

Sufficient temporal data points are crucial for MEM analysis

Abstract

Analyzing correlation functions of charmonia at finite temperature ($T$) on $32^3\times(32-96)$ anisotropic lattices by the maximum entropy method (MEM), we find that $J/\psi$ and $\eta_c$ survive as distinct resonances in the plasma even up to $T \simeq 1.6 T_c$ and that they eventually dissociate between $1.6 T_c$ and $1.9 T_c$ ($T_c$ is the critical temperature of deconfinement). This suggests that the deconfined plasma is non-perturbative enough to hold heavy-quark bound states. The importance of having sufficient number of temporal data points in the MEM analysis is also emphasized.