System-size scan of D meson R A A and v n using PbPb, XeXe, ArAr, and OO collisions at energies available at the CERN Large Hadron Collider

Experimental measurements indicate no suppression (e.g., RpPb≈1) but a surprisingly large D meson v2 was measured in p+Pb collisions. In order to understand these results, we use Trento +v-usphydro+dab−mod with event-by-event realistic hydrodynamic background to make predictions and propose a system size scan at the Large Hadron Collider (LHC) involving PbPb208, XeXe129, ArAr40, and OO16 collisions. We find that the nuclear modification factor approaches unity as the system size is decreased, but nonetheless, in the 0–10% most central collisions, v2{2} is roughly equivalent regardless of system size. These results arise from a rather nontrivial interplay between the shrinking path length and the enhancement of eccentricities in small systems at high multiplicity. Finally, we also find a surprising sensitivity of D mesons v2{2} in 0–10% at pT=2–10GeV to the slight deformation of Xe129 recently found at the LHC.