Collisional dissociation of heavy mesons in dense QCD matter

Abstract

In the framework of the reaction operator approach we calculate and resum the multiple elastic scattering of a fast $q \bar{q}$ system traversing dense nuclear matter. We derive the collisional broadening of the meson's transverse momentum and the distortion of its intrinsic light cone wave function. The medium-induced dissociation probability of heavy mesons is shown to be sensitive to the opacity of the quark-gluon plasma and the time dependence of its formation and evolution. We solve the system of coupled rate equations that describe the competition between the fragmentation of $c$- and $b$-quarks and the QGP-induced dissociation of the $D$- and $B$-mesons to evaluate the quenching of heavy hadrons in nucleus-nucleus collisions. In contrast to previous results on heavy quark modification, this approach predicts suppression of $B$-mesons comparable to that of $D$-mesons at transverse momenta as low as $p_T \sim 10$ GeV. It allows for an improved description of the large attenuation of non-photonic electrons in central Au+Au reactions at RHIC.