The R_AA and ν₂ of muons from heavy-quark decays in Pb + Pb collisions at s_NN=2.76 TeV with the ATLAS detector

The ATLAS experiment measures the production of muons coming from the decays of heavy flavour particles in the kinematic interval 4<p_T<14 GeV and |η|<1. The measurement is performed in s=2.76 GeV pp collisions and over the centrality range of (0–60)% in s_NN=2.76 TeV Pb+Pb collisions. The heavy flavour muon differential cross-sections and per-event yields are measured in pp and Pb+Pb collisions, respectively. The nuclear modification factor measured in 0–10% most central collisions is observed to be approximately equal to 0.4 and independent of p_T within uncertainties, which indicates suppressed production of heavy flavour muons in Pb+Pb collisions. The muon yields are also measured as a function of the azimuthal angle with respect to the event plane. Fourier coefficients associated with the second harmonic modulation vary slowly with p_T and show a systematic variation with centrality that is characteristic of other elliptic anisotropy measurements.