HIGH PT MEASUREMENT AT RHIC

We present recent high transverse momentum measurements in Au+Au and p+p collisions at the Relativistic Heavy Ion Collider (RHIC). We define and show the nuclear modification factor for neutral pions and charged hadrons and discuss the particle species dependence. By means of the nuclear modification factor, we observe a suppression factor at high pT of 5-6 for neutral pions and 3-4 for charged hadrons in central Au+Au collisions relative to the binary-scaled yields in p+p (or peripheral) collisions. Finally we present strong evidence for the observation of jets in Au+Au collisions and the disappearance of the away-side jet in central Au+Au collisions