Charmonium mass in hot asymmetric nuclear matter

TL;DR

This study investigates how the masses of charmonium states, including J/ψ and excited states, change in hot, asymmetric nuclear matter, highlighting significant mass drops for excited states at high densities and notable isospin effects.

Contribution

It introduces a model to calculate in-medium charmonium masses considering gluon condensates and isospin asymmetry, providing new insights into their behavior in hot, dense nuclear environments.

Findings

J/ψ mass change is small at high densities

Excited charmonium states show significant mass drops at high densities

Masses are affected by isospin asymmetry at moderate temperatures

Abstract

We calculate the in-medium masses of J/$\psi$ and of the excited states of charmonium ($\psi$(3686) and $\psi$(3770)) in isospin asymmetric nuclear matter at finite temperatures. These mass modifications arise due to the interaction of the charmonium states with the gluon condensates of QCD, simulated by a scalar dilaton field introduced to incorporate the broken scale invariance of QCD within an effective chiral model. The change in the mass of J/$\psi$ in the nuclear matter with density is seen to be rather small, as has been shown in the literature by using various approaches, whereas, the masses of the excited states of charmonium ($\psi$(3686) and $\psi$(3770)) are seen to have considerable drop at high densities. The dependence of the masses of the charmonium states on the isospin asymmetry has also been investigated in the hot nuclear matter and is seen to be appreciable at moderate temperatures and high densities. These medium modifications of the charmonium states should modify the experimental observables arising from the compressed baryonic matter produced in asymmetric heavy ion collision experiments in the future facility of FAIR, GSI.