System-size scan of D meson RAA and vn using PbPb, XeXe, ArAr, and OO collisions at energies available at the CERN Large Hadron Collider

Here, experimental measurements indicate no suppression (e.g. RpPb ~ 1) but a surprisingly large D meson v2 was measured in pPb collisions. In order to understand these results we use Trento+v-USPhydro+DAB-MOD to make predictions and propose a system size scan at the LHC involving 208PbPb, 129XeXe, 40ArAr, and 16OO 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 non-trivial 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 = 2–10 GeV to the slight deformation of 129Xe recently found at LHC.