Charm energy loss and D-D correlations from a shower picture

Abstract

Measurements of mesons containing charm or bottom quarks at high transverse momentum (P_T) constitute an interesting set of probes for the nature of the interaction of hard partons with a QCD medium as created in ultrarelativistic heavy-ion (A-A) collisions. Not only can D and B mesons to a reasonable accuracy be assumed to represent the hadronization of a b or c quark after passage through the medium, i.e. they explicitly reflect quark-medium interaction, but also their interaction physics is expected to be different from light partons traversing a medium: The quark mass restricts radiation phase space, leading to a reduction of both vacuum and medium induced radiation, a phenomenon known as the 'dead cone effect'. Due to this difference in physics, heavy quark interaction with the medium is usually treated in the leading parton energy loss approximation, whereas the theory of light parton physics has moved to modeling the full medium-modified shower evolution. In this work, an attempt is made to create a more unified description of light parton and heavy quark physics at high P_T by computing charm-medium interactions in terms of the nuclear suppression factor and back-to-back correlations using an in-medium shower evolution Monte Carlo (MC) code that is well tested for light parton physics.