Elliptic flow and Number of Constituent Quarks scaling provide crucial insights into the underlying dynamics and degrees of freedom in heavy-ion collisions. This article provides some insights on the transition from hadronic to partonic collectivity, revealing possible key signatures of medium evolution. At low energies around ($\sqrt{ s_{ \rm NN}} \leq 4.0$ GeV), $v_2$ may be negative and NCQ scaling might break down. We expect that as the collision energy rises beyond 4.0 GeV, $v_2$ may become positive and NCQ scaling gradually restores. The transition in $v_2$ behavior, coupled with the breakdown and restoration of NCQ scaling, highlights the increasing significance of partonic interactions at higher energies, marking the onset of partonic collectivity and the emergence of quark-gluon plasma (QGP)-like properties.
Categories: nucl-th hep-ph