Identified charged particle azimuthal anisotropy in PHENIX at RHIC

Event anisotropy is expected to have sensitivity to the early stage of ultra-relativistic heavy-ion collisions at RHIC. The possible formation of a quark gluon plasma (QGP) could affect how the initial anisotropy in the space coordinate is transferred into the momentum space for the final state. The anisotropy parameter (v(2)) is an amplitude of the 2nd harmonic parameter of the azimuthal distribution with respect to the reaction plane. We present here v(2) of identified and inclusive charged particles measured in the PHENIX central arm detector (\eta\ < 0.35) with respect to the reaction plane defined at \eta\ = 3 similar to 4 in 200 GeV Au+Au collisions. We find that v(2) increases from central to mid-central collisions reaching a maximum at about 50% of the geometric cross section and then decreases again for more peripheral collisions. As a function of transverse momentum in minimum-bias collisions, the v(2) parameter increases linearly with p(T) up to p(T) similar or equal to 2 GeV/c and then saturates for inclusive charged particles. the v(2) parameter of identified particles (pi(+), pi(-), K+, K-, p and (p) over bar) follow a hydro-dynamic behavior up to 2 GeV/c in PT, where the lighter mass particles have larger v(2) at a given p(T). However there is an indication that this trend is reversed at around PT similar or equal to 2 GeV/c, where p and (p) over bar have larger v(2) than pi and K.