Hard gluon evolution in the last stage of the bottom-up thermalization

Abstract

The study of how fast thermalization in heavy ion collisions occurs has been one of the central topics in the heavy ion community. In the weak coupling picture this thermalization occurs from “the bottom up”: high energy partons, formed early in the collision, radiate low energy gluons which then proceed to equilibrate among themselves, forming a thermal bath that brings the high energy sector to equilibrium. In this scheme we apply a model on parton energy loss to discuss the effects of medium expansion on the thermalization problem and estimate the average transverse momentum diffusivity for thermalization in a Bjorken expanding medium.

Evolution of hard gluons in a medium with q^(t)∼tn and the thermalization problem

“…Subsequent studies explored its application to an expanding medium (Adhya et al 2020; Caucal et al 2020), either through a modified emission rate or by equating the expanding medium to an effective static one. We employed these findings in the thermalization problem in previous papers (Ben & Machado 2022a, 2022b). In this work, we apply the formalism established in Blaizot et al (2013, 2014) and Caucal et al (2020) to analyze hard gluons traveling within a homogeneous QGP, considering $$$ \hat{q}(t)\sim {t}^n $$$, and we compare the impact of various $$$ n $$$ values on the energy distribution.…”