System size and centrality dependence of charged hadron transverse momentum spectra in Au+Au and Cu+Cu collisions at sNN=62.4 and 200 GeV

We present transverse momentum distributions of charged hadrons produced in Cu+Cu collisions at sNN=62.4 and 200 GeV. The spectra are measured for transverse momenta of 0.25<pT<5.0GeV/c at sNN=62.4GeV and 0.25<pT<7.0GeV/c at sNN=200GeV, in a pseudorapidity range of 0.2<η<1.4. The nuclear modification factor RAA is calculated relative to p+p data at both collision energies as a function of collision centrality. At a given collision energy and fractional cross section, RAA is observed to be systematically larger in Cu+Cu collisions compared to Au+Au. However, for the same number of participating nucleons, RAA is essentially the same in both systems over the measured range of pT, in spite of the significantly different geometries of the Cu+Cu and Au+Au systems.