Elliptic flow of identified hadrons in [formula presented] collisions at [formula presented]

Abstract

The anisotropy parameter ([Formula presented]), the second harmonic of the azimuthal particle distribution, has been measured with the PHENIX detector in [Formula presented] collisions at [Formula presented] for identified and inclusive charged particle production at central rapidities ([Formula presented]) with respect to the reaction plane defined at high rapidities ([Formula presented]). We observe that the [Formula presented] of mesons falls below that of (anti)baryons for [Formula presented], in marked contrast to the predictions of a hydrodynamical model. A quark-coalescence model is also investigated. © 2003 The American Physical Society.