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

The production of non-prompt D⁰ 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 sNN = 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 D⁰-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. [Figure not available: see fulltext.]