Dissociation and regeneration of charmonia within microscopic Langevin simulations

TL;DR

This paper introduces a classical Langevin simulation model to study the formation, dissociation, and regeneration of charmonia in quark-gluon plasma, analyzing their behavior at RHIC and LHC energies.

Contribution

It develops a microscopic Langevin simulation framework for charmonia dynamics, incorporating medium effects and validating equilibrium properties.

Findings

Charm and anticharm quarks reach thermal equilibrium in simulations.

Charmonia exhibit elliptic flow consistent with experimental observations.

The model reproduces key features of charmonia behavior in heavy-ion collisions.

Abstract

We present a classical model to study the formation of charmonia, as well as dissociation and regeneration processes of heavy-quark bound states in the quark gluon plasma using Langevin simulations. The charm and anticharm quarks are described as Brownian particles in the background medium of light quarks and gluons and interact among them over a Coulomb-like screened potential to form bound states, which can dissociate again due to interactions with the medium. Box simulations at fixed temperature and volume are used to verify that the system reaches the expected thermal distribution in the equilibrium limit and to test bound state properties. The medium evolution is then parametrized by a boost-invariant fireball. In this configuration, the elliptic flow of charm and anticharm quarks as well as of charmonia is studied at RHIC and LHC energies.