Measurement of beauty production via non-prompt ${\mathrm{D}}^0$ mesons in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV

Abstract

The production of non-prompt ${\mathrm{D}}^0$ mesons from beauty-hadron decays was measured at midrapidity ($\left|y\right|<0.5$) in Pb-Pb collisions at a nucleon-nucleon center-of-mass energy of $\sqrt{s_{\mathrm{NN}}}=5.02\mathrm{TeV}$ with the ALICE experiment at the LHC. Their nuclear modification factor ($R_{\mathrm{AA}}$), measured for the first time down to $p_{\mathrm{T}}=1\mathrm{GeV}/c$ in the $0-10$% and $30-50$% centrality classes, indicates a significant suppression, up to a factor of about three, for $p_{\mathrm{T}}>5\mathrm{GeV}/c$ 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 ${\mathrm{D}}^0$-meson $R_{\mathrm{AA}}$ is larger than unity for $p_{\mathrm{T}}>4\mathrm{GeV}/c$ 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.

24 pages, 4 captioned figures, authors from page 19, published version, figures at http://alice-publications.web.cern.ch/node/7637