System-size dependence of energy loss and correlations of heavy mesons at energies available at the CERN Large Hadron Collider

We study the system size dependence of heavy quark (HQ) observables at a center-of-mass energy of root sNN = 5.02 TeV to explore whether it can provide further constraints on the physical processes which are involved: energy loss of HQs in the quark gluon plasma (QGP), hadronization, and hadronic rescattering. We use the EPOS4HQ approach to study p-p and 0-10% central O-O, Ar-Ar, Kr-Kr, and Pb-Pb reactions and investigate in detail the momentum change of heavy quarks from creation until their detection as part of a hadron as well as the enhancement of heavy baryon production at low pT. We investigate furthermore the origin and the system size dependence of the azimuthal correlations between the heavy quark Q and the heavy antiquark Q<overline> and how one can bypass the problem that correlations are washed out due to the combinatorial background. We conclude that a systematic study of the system size dependence of the momentum loss allows separating the momentum loss due to the passage through the QGP from the momentum change due to hadronization, and that the QQ<overline> correlations yield insight into the different pQCD processes in which the heavy quarks are created.