  We present recent high transverse momentum measurements by the PHENIX
experiment for Au+Au and p+p collisions at $\sqrt{s_{NN}} = 200$ 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 $p_T$. We find that the ratio of $\pi^0$
to $(h^++h^-)/2$ remains nearly constant at $\sim 0.5$ for $p_T = 2-9$ GeV/c.
Finally we present strong evidence for the observation of jets in Au+Au
collisions.
