Parton collisional effect on the conversion of geometry eccentricities into momentum anisotropies in relativistic heavy-ion collisions

Abstract

We explore parton collisional effects on the conversion of geometry eccentricities into azimuthal anisotropies in Pb+Pb collisions at √ sNN = 5.02 TeV using a multi-phase transport model. The initial eccentricity εn (n = 2,3) and flow harmonics vn (n = 2,3) are investigated as a function of the number of parton collisions (N coll ) during the source evolution of partonic phase. It is found that partonic collisions leads to generate elliptic flow v2 and triangular flow v3 in Pb+Pb collisions. On the other hand, partonic collisions also result in an evolution of the eccentricity of geometry. The collisional effect on the flow conversion efficiency is therefore studied. We find that the partons with larger N coll show a lower flow conversion efficiency, which reflect differential behaviors with respect to N coll . It provides an additional insight into the dynamics of the space-momentum transformation during the QGP evolution from a transport model point of view.

Multiparticle azimuthal cumulants from transverse momentum conservation and collective flow

“…For example, hydrodynamics can transform the initial geometric asymmetry into the final momentum anisotropic flow through pressure gradient of the QGP, which can well describe the experimental results [17][18][19][20][21][22][23]. Parton cascade could achieve a similar conversion through an escape mechanism [24][25][26][27][28]. On the other hand, the initial state of color glass condensate (CGC) has also been proposed as a possible mechanism, contributing to the experimentally measured correlations in small colliding systems [29][30][31][32][33][34][35][36][37].…”