Hadron Production at Intermediate $p_T$ at RHIC

One of the most significant observation in Au+Au collisions at the
Relativistic Heavy Ion Collider (RHIC) is that hadron yields at high
transverse momentum ($p_T >$ 2 GeV/$c$) in central collisions are suppressed
with respect the number of nucleon-nucleon binary collisions scaled p+p and
peripheral Au+Au results. On the other hand, proton and antiproton yields
behave differently, no suppression at intermediate $p_T$ (2 - 5 GeV/$c$).
These experimental finding stimulates several new theoretical
interpretations on the baryon production at RHIC. In this talk, we review
the results on proton and antiproton yields in p+p, d+Au, and Au+Au
collisions at $＼sqrt{s_{NN}}$ = 200 GeV, and present the preliminary
results from 62.4 GeV in Au+Au measured by the PHENIX experiment at RHIC.