$J/\psi$ suppression in Au+Au collisions at RHIC : colour screening scenario in the bag model at variable participant numbers

TL;DR

This paper modifies the colour screening theory for $J/\psi$ suppression in heavy-ion collisions by incorporating the bag model equation of state, successfully describing RHIC data without complex medium expansion assumptions.

Contribution

It introduces a bag model-based approach to $J/\psi$ suppression, considering sequential melting and longitudinal expansion, aligning theory with experimental RHIC results.

Findings

Model accurately fits PHENIX data at mid-rapidity

Sequential melting of charmonium states is incorporated

No need for (3+1)-D expansion in the model

Abstract

We have modified the colour screening theory of Chu and Matsui by properly incorporating bag model equation of state for quark gluon plasma (QGP). We have also chosen the pressure parametrization rather than parametrizing energy density in the transverse plane. We assume that the QGP dense medium is expanding in the longitudinal direction obeying Bjorken boost invariant scaling law. Sequential melting of $\chi_c$, $\psi^{'}$ and $J/\psi$ is also considered in this scenario. We have applied above formulation to the recent PHENIX experimental data of $J/\psi$ suppression in Au + Au collisions at RHIC. We find that the model gives a good description of data at mid-rapidity in terms of survival probability versus number of participants without any necessity of implementing (3+1)-dimensional expansion of the deconfined medium.