Separating non-collective effects in d-Au collisions

Abstract

In this letter, we present the multiplicity and yields of charged hadrons and particle ratios in d-Au collisions at $\sqrt{s_{NN}}= 200$ GeV using the PYTHIA8/Angantyr. The model reproduces the multiplicity ($N_{ch}$) and pseudo-rapidity distribution reasonably well in minimum-biased d-Au collisions without assuming the formation of a thermalized medium. The invariant yield from Angantyr underpredicts the data in central collisions. We discussed the similarity between the nuclear modification factor $R_{AA}$ and data/MC from Angantyr and the possibility of using it as an alternative to check in-medium effects. The data/MC suggests that the central d-Au collisions exhibit signals like baryon enhancement, but no high $p_T$ suppression was found. The d-Au collisions have a much smaller invariant yield than the thermal model calculation for similar $N_{part}$. Based on the available data and simulation results, we argue that a medium may form in the central d-Au collision, but it differs from the perfect QGP formed in Pb-Pb collisions at LHC.