A microscopic calculation of fission cross sections with the non-equilibrium Green function method

We apply the non-equilibrium Green function (NEGF) method to microscopically evaluate fission cross sections for the neutron induced $^{235}$U$(n,f)$ reaction. While the model space was restricted only to seniority zero configurations in the previous applications of the NEGF method, we remove this restriction and include seniority non-zero configurations as well. In such model space, a proton-neutron interaction is active, for which we introduce a random interaction. We find that the seniority non-zero configurations significantly increase the fission cross sections, and thus the fission-to-capture branching ratios, even though they are still underestimated by about one order of magnitude as compared to the experimental data. In addition, we also find that the fission dynamics is governed by only a small number of eigenstates of the model Hamiltonian.

K. Uzawa, K. Hagino · 2025