With the use of an incoherent binary nucleon-nucleon collision model of AA collisions for simulating particle production, it is demonstrated that R_AA and R_CP are less than unity for hard scattering in the absence of any nuclear modification effects. R_dAu is also shown to approach or exceed unity only if p_T broadening is taken into account. With a simple phenomenological parameter, the mean nucleon energy loss fraction, this model yields distributions that are comparable to those of experiment. The nuclear geometry is described by the Glauber model, and particle production is simulated by the PYTHIA event generator.