Novel heavy flavour suppression mechanisms in the QGP

Abstract

We revisit the question of the measured, unexpectedly large, heavy flavour suppression, RAA(pT) ≪ 1, in nucleus–nucleus collisions at RHIC and compare two new theoretical approaches to the D- and B-meson quenching. In the first model, radiative energy loss, collisional energy loss and heavy quark–resonance interactions are combined to evaluate the drag and diffusion coefficients in the quark–gluon plasma and the mixed phase. These are applied in a relativistic Fokker–Planck equation to simulate the heavy c- and b-quark suppression rate and elliptic flow v2(pT). In the second model, the fragmentation probability for heavy quarks and the medium-induced decay probability for heavy hadrons are derived. These are implemented in a set of coupled rate equations that describe the attenuation of the observable spectra from the collisional dissociation of heavy mesons in the QGP. An improved description of the non-photonic electron RAA(pT) at RHIC can be obtained. In contrast to previous results, the latter approach predicts suppression of B-mesons comparable to that of D-mesons at transverse momenta as low as pT ∼ 10 GeV.