  We investigate the suppression factor and the azimuthal correlation function
for high $p_T$ hadrons in central Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV
by using a dynamical model in which hydrodynamics is combined with explicitly
traveling jets. We study the effects of parton energy loss in a hot medium,
intrinsic $k_T$ of partons in a nucleus, and $p_{\perp}$ broadening of jets on
the back-to-back correlations of high $p_T$ hadrons. Parton energy loss is
found to be a dominant effect on the reduction of the away-side peaks in the
correlation function.
