Insight from the elliptic flow of identified hadrons measured in relativistic heavy-ion collisions

Abstract

In this paper, we have discussed the transverse momentum dependence of elliptic flow measured in relativistic heavy-ion collisions. Under the assumption of quark recombination model, [Formula: see text] of light and strange quarks is obtained from the measured [Formula: see text] of identified hadrons. The [Formula: see text] of strange quarks obtained from [Formula: see text]-meson [Formula: see text] is found to be similar to that of from [Formula: see text] [Formula: see text] in Au+Au collisions at [Formula: see text][Formula: see text]GeV. This may indicate that both [Formula: see text] and [Formula: see text] are produced through quark recombination at top RHIC energy. However, we find that the [Formula: see text] of light quarks is consistently higher than that of strange quarks at the low transverse momentum. We have shown that [Formula: see text] of light and strange quarks is consistent with each other when plotted as a function of its transverse kinetic energy. The observed scaling of [Formula: see text] works at both RHIC and LHC energies. It is also shown that the observed scaling holds for other flow harmonics, e.g., [Formula: see text]. The new observed scaling is purely empirical and needs more theoretical input to understand the physics behind it.