Azimuthal Anisotropy Measurements by STAR

Abstract

The recent study of centrality and transverse momentum ($p_T$) dependence of inclusive charged hardron elliptic anisotropy ($v_2$) at midrapidity ($|\eta |<1.0$) in Au+Au collision at $\sqrt{s_{NN}}=$ 7.7, 11.5, 19.6, 27, and 39 GeV in STAR Beam Energy Scan program is presented. We show that the observed increase of inclusive $v_2$ is mainly due to the average $p_T$ increase with energy. In Au+Au 200 GeV collisions, the triangular anisotropy ($v_3$) measurements highly depend on measurment methods; $v_3$ is strongly dependent on $\Delta \eta$. The difference between two- and four-particle cumulants $v_2\{2\}$ and $v_2\{4\}$ for Au+Au and Cu+Cu collision at $\sqrt{s_{NN}}=$ 62.4 and 200 GeV is used to explore flow fluctuations. Furthermore, by exploiting the symmetry of average flow in pseudorapidity $\eta$ about mid-rapidty, the $\Delta \eta$-dependent and independent components are seperated using $v_2\{2\}$ and $v_2\{4\}$.

References in corpus (6)

• Inclusive charged hadron elliptic flow in Au + Au collisions at $\sqrt{s_{NN}}$ = 7.7 - 39 GeV
• Third Harmonic Flow of Charged Particles in Au+Au Collisions at sqrtsNN = 200 GeV
• Collision Energy Dependence of Viscous Hydrodynamic Flow in Relativistic Heavy-Ion Collisions
• Event-plane decorrelation over pseudo-rapidity and its effect on azimuthal anisotropy measurement in relativistic heavy-ion collisions
• Decomposition of flow and nonflow in relativistic heavy-ion collisions
• Isolation of Flow and Nonflow by Two- and Multi-Particle Cumulant Measurements of $v_n$ in $\sqrt{s_{NN}}=200$ GeV Au+Au Collisions by STAR