B meson production in Pb+Pb at 5.02 ATeV at LHC: Estimating the diffusion coefficient in the infinite mass limit

Abstract

In the last decade a Quasi-Particle Model (QPM) has been developed to study charm quark dynamics in ultra-relativistic heavy-ion collisions supplying a satisfactory description of the main observables for D meson and providing an estimate of the space-diffusion coefficient Ds(T) from the phenomenology. In this paper, we extend the approach to bottom quarks describing their propagation in the quark-gluon plasma within an event-by-event full Boltzmann transport approach followed by a coalescence plus fragmentation hadronization. We find that QPM approach is able to correctly predict the first available data on RAA(pT) and v2(pT) of single-electron from B decays without any parameter modification w.r.t. the charm. We show also predictions for centralities where data are not yet available for both v2(pT) and v3(pT). Moreover, we discuss the significant breaking of the expected scaling of the thermalization time τth with MQ/T, discussing the evolution with mass of Ds(T) to better assess the comparison to lQCD calculations. We find that at T=Tc charm quark Ds(T) is about a factor of 2 larger than the asymptotic value for M→∞, while bottom Ds(T) is only a 20% higher. This implies a Ds(T) which is consistent within the current uncertainty to the most recent lattice QCD calculations with dynamical quarks for M→∞.

Keywords

• Relativistic heavy-ion collisions
• Quark-gluon plasma
• Heavy quark transport
• Heavy flavour hadronization