Anisotropic flow at RHIC

Abstract

We present the first measurement of directed flow ($v_1$) at the Relativistic Heavy Ion Collider (RHIC). $v_1$ is found to be consistent with zero at pseudorapidities $\eta$ from -1.2 to 1.2, then rises to the level of a couple of percent over the range $2.4 < |\eta| < 4$. The latter observation is similar to that from NA49 if the SPS rapidities are shifted by the difference in beam rapidity between RHIC and SPS. We studied the evolution of elliptic flow from p+p collisions through d+Au collision, and onto Au+Au collisions. Measurements of higher harmonics are presented and discussed.