Monte Carlo calculations of two-neutron transfer cross sections

Differential cross sections for (t, p) and (p, t) reactions have been calculated in finite-range distorted-wave Born approximation, with the Monte Carlo method used to evaluate the six-dimensional integrals. The use of the Monte Carlo method makes it possible to treat cases of non-zero angular momentum transfer. Angular distributions and relative cross sections are in good agreement with those given by the zero-range approximation. The cross sections of unnatural-parity transitions, as calculated by our one-step finite-range DWBA, are several orders of magnitude smaller than experimental data, suggesting the importance in these reactions of two-step processes.