"fig5_b Z=1 hadrons FOPI" of "Disappearance of partonic collectivity in $\sqrt{s_{NN}}$ = 3 GeV Au+Au collisions at RHIC"

We report on the measurements of directed flow $v_1$ and elliptic flow $v_2$ for hadrons $(\pi^{\pm}, K^{\pm}, K_S^0, p, \phi, \Lambda$ and $\Xi^-)$ from Au+Au collisions at $\sqrt{s_{NN}} $ = 3GeV and $v_2$ for $(\pi^{\pm}, K^{\pm}$, $p$ and $\bar{p})$ at 27 and 54.4 GeV with the STAR experiment. While at the two higher energy midcentral collisions the number-of-constituent-quark (NCQ) scaling holds, at 3 GeV the $v_{2}$ at midrapidity is negative for all hadrons and the NCQ scaling is absent. In addition, the $v_1$ slopes at midrapidity for almost all observed hadrons are found to be positive, implying dominant repulsive baryonic interactions. The features of negative $v_2$ and positive $v_1$ slope at 3 GeV can be reproduced with a baryonic mean-field in transport model calculations. These results imply that the medium in such collisions is likely characterized by baryonic interactions.