摘要
The production of non-prompt D-0 mesons from beauty-hadron decays was measured at midrapidity (vertical bar y vertical bar < 0.5) in Pb-Pb collisions at a nucleon-nucleon center-of-mass energy of root s(NN) = 5.02TeV with the ALICE experiment at the LHC. Their nuclear modification factor (R-AA), measured for the first time down to p(T) = 1 GeV/ c in the 0-10% and 30-50% centrality classes, indicates a significant suppression, up to a factor of about three, for p(T) > 5 GeV/ c in the 0-10% central Pb-Pb collisions. The data are described by models that include both collisional and radiative processes in the calculation of beauty-quark energy loss in the quark-gluon plasma, and quark recombination in addition to fragmentation as a hadronisation mechanism. The ratio of the non-prompt to prompt D-0-meson R-AA is larger than unity for p(T) > 4 GeV/c in the 0-10% central Pb-Pb collisions, as predicted by models in which beauty quarks lose less energy than charm quarks in the quark-gluon plasma because of their larger mass.