Speaker
Description
Elliptic flow ($v_{2}$) is the second harmonic coefficient in the Fourier expansion of the azimuthal distribution of produced particles, relative to the reaction plane, in heavy-ion collisions. This observable is particularly sensitive to the early-stage dynamics of the system’s evolution and provides insights into the degrees of freedom within the medium.
In this talk, we will report $v_{2}$ measurements for a variety of hadrons, including $\pi^{\pm}$, $K^{\pm}$, $p$, $\overline{p}$, $K^{0}_{S}$, $\phi$, $\Lambda$, $\overline{\Lambda}$, $\Xi^{\pm}$ and $\Omega^{\pm}$, based on high-statistics datasets from the second phase of the RHIC Beam Energy Scan (BES-II) program at STAR. The scaling of $v_{2}$ according to the Number of Constituent Quarks (NCQ) for both particles and antiparticles will be examined. Additionally, the NCQ-scaled $v_{2}$ ratios, such as $\pi^{+}$/$K^{+}$, $p$/$K^{+}$, $\pi^{-}$/$K^{-}$, $\overline{p}$/$K^{-}$, $\phi$/$K^{-}$, $\Lambda$/$K^{0}_{S}$ and $\overline{\Lambda}$/$K^{0}_{S}$, across the energy range $\sqrt{s_{NN}}$ = 7.7, 9.2, 11.5, 14.6, 17.3 and 19.6 GeV will be presented. The experimental measurements will be compared with various model calculations, and the resulting insights will be discussed.
