Collisional energy loss of nonasymptotic jets in a quark-gluon plasma

Abstract

We calculate the collisional energy loss suffered by a heavy (charm) quark created at a finite time within a quark-gluon plasma in the classical linear response formalism as in Peigne et al. [J. High Energy Phys. 04 (2006) 011]. We pay close attention to the problem of formulating a suitable current and the isolation of binding and radiative energy loss effects. We find that unrealistic large binding effects arising in previous formulations must be subtracted. The finite time correction is shown to be important only for very short length scales on the order of a Debye length. The overall energy loss is similar in magnitude to the energy loss suffered by a charge created in the asymptotic past. This result has significant implications for the relative contribution to energy loss from collisional and radiative sources and has important ramifications for the ``single electron puzzle'' at the BNL Relativistic Heavy Ion Collider.