High pT measurements from PHENIX Original Research Article

We present recent high transverse momentum measurements by the PHENIX experiment for Au+Au and p+p collisions at View the MathML source GeV at the Relativistic Heavy Ion Collider (RHIC). We show particle spectra for neutral pions and charged hadrons, define and show the nuclear modification factor, and discuss particle composition. By means of the nuclear modification factor, we observe a suppression factor of 5–6 for neutral pions and 3–4 for charged hadrons in central collisions at high pT. We find that the ratio of π0 to (h+ + h−)/2 remains nearly constant at ∼ 0.5 for pT = 2 − 9GeV/c. Finally we present strong evidence for the observation of jets in Au+Au collisions.