Consequences of a Λc/D enhancement effect on the non-photonic electron nuclear modification factor in central heavy ion collisions at RHIC energy

The RHIC experiments have measured the nuclear modification factor R-AA of non-photonic electrons in Au + Au collisions at root(NN)-N-S = 200 GeV. This R-AA exhibits a large suppression for p(t) > 2 GeV/c which is commonly attributed to heavy-quark energy loss. It is expected that the heavy-quark radiative energy loss is smaller than the light quark one because of the so-called dead-cone effect. An enhancement of the charm baryon yield with respect to the charm meson yield, as it is observed for light and strange hadrons, can explain part of the suppression. This phenomenon has been put forward in a previous work. We present in this Letter a more complete study based on a detailed simulation which includes electrons from charm and bottom decay, charm and bottom quark realistic energy loss as well as a more realistic modeling of the Lambda(c)/D enhancement. We show that a Lambda(c)/D ratio close to unity, as observed for light and strange quarks, could explain 20-25% of the suppression of non-photonic electrons in central Au + Au collisions. This effect remains significant at relatively high non-photonic electron transverse momenta of 8-9 GeV/c. (C) 2008 Elsevier B.V. All rights reserved.