BAMPS with the improved Gunion–Bertsch matrix element

Abstract

Abstract Focusing on the simultaneous investigation of the hard and the soft regime of ultra-relativistic heavy-ion collisions at the Relativistic Heavy-Ion Collider (RHIC) at the Brookhaven National Laboratory (BNL) and the Large Hadron Collider (LHC) at CERN, we present our recent results on the nuclear modification factor R AA and the elliptic flow v 2 within the partonic transport model BAMPS (Boltzmann Approach to Multi-Parton Scatterings). While using interactions provided by perturbative QCD, BAMPS allows the full 3+1D simulation of the quark–gluon plasma (QGP) at the microscopic level by solving the relativistic Boltzmann equation for quarks and gluons. The microscopic interactions include both elastic 2 → 2 collisions, calculated by screened leading order pQCD matrix elements, and inelastic 2 ↔ 3 processes, calculated within an improved Gunion–Bertsch approximation. Furthermore, for all partonic processes a microscopic, running coupling is explicitly taken into account. We show that when fixing the parameter X LPM resulting from the effective modeling of the Landau–Pomeranchuk–Migdal effect, we find not only a good description of R AA at both RHIC and LHC, but also a sizable elliptic flow is built up within the partonic phase.