System-size independence of directed flow at the Relativistic Heavy-Ion Collider

STAR Collaboration, B. I. Abelev

We measure directed flow ($v_1$) for charged particles in Au+Au and Cu+Cu collisions at $\sqrt{s_{NN}}=$ 200 GeV and 62.4 GeV, as a function of pseudorapidity ($\eta$), transverse mo…