Measurement of beauty production via non-prompt D0 mesons in Pb-Pb collisions at √sNN = 5.02 TeV

A bstract The production of non-prompt D 0 mesons from beauty-hadron decays was measured at midrapidity (| y | < 0 . 5) in Pb-Pb collisions at a nucleon-nucleon center-of-mass energy of $$ \sqrt{{\textrm{s}}_{\textrm{NN}}} $$ s NN = 5 . 02 TeV 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.