Di-hadron azimuthal correlation and Mach-like cone structure in parton/hadron transport model

In a framework of a multi-phase transport model with both partonic and hadronic interactions, azimuthal correlations between trigger particles and associated scattering particles (3 < p T < 6 GeV/c and 0.15 < p T < 3 GeV/c (soft), or 2.5 < p trig T < 4 GeV/c and 1 < p assoc T < 2.5 GeV/c (hard)) in Au + Au collisions at √ sNN = 200 GeV have been studied by the mixing-event technique, and Mach-like structure has been observed in correlation function for central collisions. By comparing the scenarios with and without parton cascade and/or hadronic rescattering, it is shown that both partonic and hadronic dynamical mechanisms contribute to the Mach-like structure of the scattered particle azimuthal correlations. It was pointed out that the contribution of hadronic dynamical process can not be ignored in the emergence of Mach-like correlations of the soft scattered associated hadrons. However, only hadronic rescattering is not able to reproduce experimental amplitude of Mach-like cone on away-side, and instead the parton cascade process is essential to describe experimental amplitude of Mach-like cone on away-side. In addition, it was found that both the associated multiplicity and the magnitude sum of pT decrease with impact parameter but 〈pT 〉 increases with impact parameter within string melting AMPT model.