Nuclear modification factor of nonphotonic electrons in heavy-ion collisions, and the heavy-flavor baryon-to-meson ratio

Journals published by the American Physical Society can be found at http://publish.aps.org/The nuclear modification factor R(AA) of nonphotonic electrons in Au + Au collisions at root(S)NN = 200 GeV is studied by considering the decays of heavy-flavor hadrons produced in a quark coalescence model. Although an enhanced Lambda(c)/D(0) ratio is predicted by the coalescence model, it is peaked at small transverse momenta (similar to 2 GeV) due to the large difference between heavy and light quark masses. As a result, the enhanced Lambda(c)/D(0) ratio, which is expected to suppress the electron R(AA) as the branching ratio of Lambda(c) decay into electrons is smaller than that of D(0), does not lead to additional suppression of the electron R(AA) at large transverse momenta (>= 5 GeV), where the suppression is mainly due to heavy quark energy loss in produced quark-gluon plasma. Also, the enhanced Lambda(b)/(B) over bar (0) ratio predicted by the coalescence model has even smaller effect on the nonphotonic electron R(AA) as bottom baryons and mesons have similar branching ratios for semileptonic decays into electrons