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Physics Letters B 663 (2008) 55-60
Consequences of a $\Lambda_c/D$ enhancement effect on the non-photonic electron nuclear modification factor in central heavy ion collisions at RHIC energy
G. Martinez-Garcia1, S. Gadrat1, P. Crochet2

The RHIC experiments have measured the nuclear modification factor R_AA of non-photonic electrons in Au+Au collisions at sqrt(s) = 200 GeV. This R_AA exhibits a large suppression for pt > 2 GeV/c which is commonly attributed to heavy-quark energy loss. In order to reproduce satisfactorily the data, energy-loss models assume a heavy-quark energy loss similar to that of light quarks. However, 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 paper 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.
1 :  SUBATECH - Laboratoire SUBATECH Nantes
2 :  LPC - Laboratoire de Physique Corpusculaire [Clermont-Ferrand]
Physique/Physique des Hautes Energies - Phénoménologie
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