Prompt and non-prompt J/$\psi$ production and nuclear modification at mid-rapidity in p-Pb collisions at $\sqrt{s_{\text{NN}}}=5.02$ TeV

Abstract

A measurement of beauty hadron production at mid-rapidity in proton-lead collisions at a nucleon-nucleon centre-of-mass energy $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV is presented. The semi-inclusive decay channel of beauty hadrons into J/$\psi$ is considered, where the J/$\psi$ mesons are reconstructed in the dielectron decay channel at mid-rapidity down to transverse momenta of 1.3 GeV/$c$. The $\mathrm{b}\overline{\mathrm{b}}$ production cross section at mid-rapidity, $\mathrm{d}{\sigma }_{\mathrm{b}\overline{\mathrm{b}}}/\mathrm{d}y$, and the total cross section extrapolated over full phase space, ${\sigma }_{\mathrm{b}\overline{\mathrm{b}}}$, are obtained. This measurement is combined with results on inclusive J/$\psi$ production to determine the prompt J/$\psi$ cross sections. The results in p-Pb collisions are then scaled to expectations from pp collisions at the same centre-of-mass energy to derive the nuclear modification factor $R_{\mathrm{pPb}}$, and compared to models to study possible nuclear modifications of the production induced by cold nuclear matter effects. $R_{\mathrm{pPb}}$ is found to be smaller than unity at low $p_{\mathrm{T}}$ for both J/$\psi$ coming from beauty hadron decays and prompt J/$\psi$.

24 pages, 7 captioned figures, 3 tables, authors from page 18, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/4173