Elliptic Flow of Charm and Strange Hadrons in High-Multiplicity p+Pb Collisions at sqrt[s_NN]=8.16 TeV

The elliptic azimuthal anisotropy coefficient (v_2) is measured for charm (D^0) and strange (K_S^0, Λ, Ξ^-, and Ω^-) hadrons, using a data sample of p+Pb collisions collected by the CMS experiment, at a nucleon-nucleon center-of-mass energy of sqrt[s_NN]=8.16  TeV. A significant positive v_2 signal from long-range azimuthal correlations is observed for all particle species in high-multiplicity p+Pb collisions. The measurement represents the first observation of possible long-range collectivity for open heavy flavor hadrons in small systems. The results suggest that charm quarks have a smaller v_2 than the lighter quarks, probably reflecting a weaker collective behavior. This effect is not seen in the larger PbPb collision system at sqrt[s_NN]=5.02  TeV, also presented.