Measurement of Prompt D^0 Meson Azimuthal Anisotropy in Pb-Pb Collisions at sqrt[s_NN]=5.02 TeV

The prompt D^0 meson azimuthal anisotropy coefficients, v_2 and v_3, are measured at midrapidity (|y|<1.0) in Pb-Pb collisions at a center-of-mass energy sqrt[s_NN]=5.02  TeV per nucleon pair with data collected by the CMS experiment. The measurement is performed in the transverse momentum (p_T) range of 1 to 40  GeV/c, for central and midcentral collisions. The v_2 coefficient is found to be positive throughout the p_T range studied. The first measurement of the prompt D^0 meson v_3 coefficient is performed, and values up to 0.07 are observed for p_T around 4  GeV/c. Compared to measurements of charged particles, a similar p_T dependence, but smaller magnitude for p_T<6  GeV/c, is found for prompt D^0 meson v_2 and v_3 coefficients. The results are consistent with the presence of collective motion of charm quarks at low p_T and a path length dependence of charm quark energy loss at high p_T, thereby providing new constraints on the theoretical description of the interactions between charm quarks and the quark-gluon plasma.