Non-perturbative collective inertias for fission: a comparative study

TL;DR

This study extends non-perturbative methods for calculating collective inertias in nuclear fission, comparing them with perturbative and exact GCM results, and finds non-perturbative inertias to be more accurate and structurally consistent.

Contribution

It introduces a non-perturbative approach to compute GCM inertias with density-dependent forces and demonstrates its accuracy against exact GCM calculations.

Findings

Non-perturbative inertias are similar to exact GCM inertias.

Non-perturbative inertias exhibit richer structure than perturbative ones.

A phenomenological factor can align non-perturbative inertias with exact GCM results.

Abstract

The non-perturbative method to compute Adiabatic Time Dependent Hartree Fock Bogoliubov (ATDHFB) collective inertias is extended to the Generator Coordinate Method (GCM) including the case of density dependent forces. The two inertias schemes are computed along the fission path of the $^{234}$U and compared with the perturbative results. We find that the non-perturbative schemes predict very similar collective inertias with a much richer structure than the one predicted by perturbative calculations. Moreover, the non-perturbative inertias show an extraordinary similitude with the exact GCM inertias computed numerically from the energy overlap. These results indicate that the non-perturbative inertias provide the right structure as a function of the collective variable and only a phenomenological factor is required to mock up the exact GCM inertia, bringing new soundness to the microscopic description of fission.