Study of azimuthal anisotropy of charged hadrons at high p_T in Au+Au collisions at &[root]s_NN = 200GeV at RHIC-PHENIX

The azimuthal anisotropy coefficient v₂ is a good tool to investigate properties of the Quark Gluon Plasma (QGP). It can study not only the collective behavior of the medium, but also the energy loss of hard scattered partons in it. The non-central collisions yield the collision areas with elliptic shape. When the hard scattered partons created in the collisions are emitted, they have different path-lengths of interacting with QGP depending on their emission angles with respect to the reaction plane. This will result in the difference of the yields of high transverse momentum (p_T) particles in in-plane and out-of-plane. Therefore, the energy loss mechanism can be investigated by measuring the v₂ at high p_T. We have recently improved the precision of the charge hadron v₂ measurement by reducing background tracks using the silicon vertex tracker installed in PHENIX. In this presentation, we discuss the collision centrality dependence and p_T dependence of charged hadron v₂ in Au+Au collisions at √s_NN=200GeV from the data collected by PHENIX during the RHIC Year-2014 run. We also discuss the path-length dependence of the energy loss utilizing the v₂ measurement.