Possible Evidence for Radial Flow of Heavy Mesons in d+Au Collisions

Recent measurements of particle correlations and the spectra of hadrons at both RHIC and the LHC are suggestive of hydrodynamic behavior in very small collision systems (p+Pb, d+Au and p+p collisions). The measurements are both qualitatively and quantitatively similar to what is seen in central heavy ion collisions where low viscosity hot nuclear matter is formed. While light quarks and gluons are thought to make up the bulk matter, one of the most surprising results in heavy ion collisions is that charm quarks also have a large $v_2$, suggesting that they too participate in the matter. Measurements of the transverse momentum spectra of electrons from the decay of $D$ and $B$ mesons in d+Au show an enhancement in central collisions relative to p+p. We employ the blast-wave model to determine if the flow of heavy quarks in d+Au and p+Pb data is able to explain the enhancement observed in the data. We find a reasonable description of the data with blast-wave parameters extracted from fits to the light hadron spectra, suggesting hydrodynamics as a possible explanation.Comment: final published versio