  The PHOBOS collaboration has measured transverse momentum distributions of
charged hadrons produced in Cu+Cu collisions at sqrt(s_(NN)) = 200 and 62.4
GeV. The nuclear modification factor R_(AA)^(Npart) is calculated relative to
p+p data at both collision energies as a function of collision centrality. For
the same number of participating nucleons, R_(AA)^(Npart) is essentially the
same in both systems over the full range of p_(T) that is measured. In
addition, we observe that within experimental uncertainties, the ratio of 200
GeV to 62.4 GeV Cu+Cu yields has only a moderate centrality dependence and is
consistent with the value previously measured in Au+Au collisions for a broad
range of p_(T).
