Bottomonium suppression: A probe to the pre-equilibrium era of quark matter

Abstract

We have studied the thermal suppression of the bottomonium states in relativistic heavy-ion collision at LHC energies as function of centrality, rapidity, transverse momentum etc. to explain the CMS data. Our investigation mainly spans over three problems: a) how the theoretical predictions might still be modified by the remnants of the non-perturbative confining force, b) how does the presence of a not necessarily isotropic QCD medium modify the potential (both the real and imaginary part) acting between a static quark and antiquark pair, and c) finally how the additional time-zone of pre-equilibrium partonic evolution, in addition to the above modifications, affects the bottomonium production at the LHC energies. We resolve them by correcting both the perturbative and nonperturbative terms of the $Q\bar Q$ potential in (an)isotropic QCD medium and then couple to the dynamics of the system undergoing successive pre-equilibrium and equilibrium era. Due to the tiny formation time and the large binding energy of bottomonium (1S) state, we succeed in constraining the isotropization time and the shear viscosity.