Angular correlations in heavy ion reactions

We examine the properties of the in-plane correlation between the initial scattering angle and the angle at which subsequent particle decay occurs, following a forward angle heavy ion reaction. The results are obtained in the strong absorption limit. In particular, we explain the recent experimental observation that there is a systematic spin-dependence of the correlation distributions on the initial scattering angle of the excited nucleus. We generalize this result to the case of nuclei with non-zero spins in the decay channel, and we also obtain closed form expressions for the correlation function under general matching conditions. (orig.)