  Single prompt photon and pion spectra in p-p and Au-Au collisions at
intermediate RHIC energy, s^1/2 = 62.4 GeV, are computed at large transverse
momentum in perturbative QCD. Next-to-leading order calculations in p-p
scattering are first presented. The quenching of the prompt photon and pion
yield due to energy loss processes in central Au-Au with respect to p-p
collisions is then predicted. At this energy, the small phase-space available
to produce hard partons makes the pion quenching almost as pronounced as at
s^1/2 = 200 GeV, despite the smaller gluon density of the produced medium. In
the photon sector, energy loss effects prove small because of this very
phase-space restriction, which favours the direct production channel. A
significant suppression of high-pt photons is however predicted, because of a
strong isospin effect together with the depletion of nuclear parton densities
at large x.
