Exchange effects in nucleus-nucleus reactions

We present a scattering model for nuclei with similar masses. In this three-body model, the projectile has a core+valence structure, whereas the target is identical to the core nucleus. The three-body wave functions must be symmetrized for the exchange of the cores. This property gives rise to nonlocal potentials, which are computed without approximation. The present model is an extension of the continuum discretized coupled channel formalism, with an additional treatment of core exchange. We solve the coupled-channel system, including nonlocal terms, by the R-matrix method using Lagrange functions. This model is applied to the C-13 + C-12, N-13 +C-12 and O-16 + C-12 systems. Experimental scattering cross sections are fairly well reproduced without any parameter fitting. The backward-angle enhancement of the elastic cross sections is due to the nonlocal potential. We discuss in more detail the various nonlocal contributions and present effective local potentials.

Automated summary

The model presents a scattering model for nuclei with similar masses, incorporating core exchange treatment. The coupled-channel system is solved using the R-matrix method, including nonlocal terms. Experimental scattering cross sections are well reproduced without parameter fitting.