Measurement of the centrality dependence of open heavy flavour production in lead-lead collisions at sqrts = 2.76 TeV with the ATLAS detector

Measurements of heavy quark production and suppression in ultra-relativistic nuclear collisions probe the interactions of heavy quarks with the hot, dense medium created in the collisions. ATLAS has measured heavy quark production in sqrts = 2.76 TeV Pb+Pb collisions via semi-leptonic decays of open heavy flavour hadrons to muons. Results obtained from an integrated luminosity of approximately 7/mub collected in 2010 are presented for the per-event muon yield as a function of muon transverse momentum, pT, over the range of 4 <pT < 14 GeV. Over that momentum range single muon production results largely from heavy quark decays. The centrality dependence of the muon yields is characterized by the "central to peripheral'' ratio, Rcp. Using this measure, muon production from heavy quark decays is found to be suppressed by a centrality-dependent factor that increases smoothly from peripheral to central collisions. Muon production is suppressed by approximately a factor of 2.5 in central collisions relative to peripheral collisions. Within the experimental errors, the observed suppression is independent of muon pT for all centralities.