Production of muons from heavy-flavour hadron decays at forward rapidity in Pb--Pb collisions at $\sqrt{s_{\rm NN}} = 5.02~{\rm TeV}$}

Abstract

The measurement of the production of single muons from heavy-flavour hadron decays at forward rapidity in Pb--Pb collisions at $\sqrt{s_{\rm NN}} = 5.02~{\rm TeV}$ collected in 2015 is presented as a function of transverse momentum ($p_{\rm T}$) and collision centrality. A strong suppression of the yield is observed at high $p_{\rm T}$ in the most central collisions compared to the binary-scaled expectation from pp collisions at the same energy. The $p_{\rm T}$-integrated nuclear modification factor ($R_{\rm AA}$) as function of the number of participating nucleons indicates an increase of the suppression from peripheral to central collisions. Comparisons with the results for Pb--Pb collisions at $\sqrt{s_{\rm NN}} = 2.76~{\rm TeV}$ and with transport model predictions are shown. A similar suppression is measured at both $\sqrt{s_{\rm NN}} = 2.76~{\rm TeV}$ and 5.02 TeV. The results available from $p_{\rm T} =$7 GeV/$c$ up to $p_{\rm T} =~$20 GeV/$c$, will provide new constraints on transport model ingredients and new insights on the understanding of the evolution of the hot and dense matter formed in ultra-relativistic heavy-ion collisions.