Measurement of D0 Azimuthal Anisotropy at Midrapidity in Au + Au Collisions at √ s N N = 200 GeV
Physical Review Letters
We report the first measurement of the elliptic anisotropy (v2) of the charm meson D0 at midrapidity (|y|<1) in Au+Au collisions at √sNN=200 GeV. The measurement was conducted by the STAR experiment at RHIC utilizing a new high-resolution silicon tracker. The measured D0 v2 in 0%–80% centrality Au+Au collisions can be described by a viscous hydrodynamic calculation for a transverse momentum (pT) of less than 4 GeV/c. The D0 v2 as a function of transverse kinetic energy (mT−m0, where mT=√p2T+m20) is consistent with that of light mesons in 10%–40% centrality Au+Aucollisions. These results suggest that charm quarks have achieved local thermal equilibrium with the medium created in such collisions. Several theoretical models, with the temperature-dependent, dimensionless charm spatial diffusion coefficient (2πTDs) in the range of ∼2–12, are able to simultaneously reproduce our D0 v2 result and our previously published results for the D0 nuclear modification factor.
Gibson, Adam; Stanisalus, Shirvel; Koetke, Donald D.; and ., STAR Collaboration, et al, "Measurement of D0 Azimuthal Anisotropy at Midrapidity in Au + Au Collisions at √ s N N = 200 GeV" (2017). Physics and Astronomy Faculty Publications. 165.