J/psi with large pT probing the early stage of relativistic heavy ion collisions

TL;DR

This paper investigates how high transverse momentum J/psi particles can serve as probes of the initial conditions and early evolution of quark-gluon plasma in heavy ion collisions, using a transport model.

Contribution

It demonstrates that high pT J/psi production is sensitive to initial energy density, providing a new way to study early QGP dynamics.

Findings

High pT J/psi production depends on initial energy density.

Charmonium yields at low pT are dominated by recombination.

J/psi nuclear modification factor shows weak dependence on shear viscosity.

Abstract

We study the charmonium suppression in different evolutions of quark gluon plasma (QGP) based on the transport model. In the colliding energies of Large Hadron Collider, charmonium final yields are dominated by the recombination of charm and anti-charm quarks in the deconfined phase. Heavy quark diffusions depend less on the shear viscosity of the bulk medium, which makes the J/psi nuclear modification factor in the entire pT bin shows weak dependence on the shear viscosity of QGP. However, charmonium with high transverse momentum pT, can only be produced in the early stage of nuclear collisions, and is sensitive to the initial energy density (or temperature) of QGP, and can be a probe of the initial dynamical evolutions of quark gluon plasma.