New dynamical pair breaking effect

TL;DR

This paper introduces a new dynamical pair breaking effect observed at low energies, using time-dependent equations to model Cooper pair destruction and creation in superfluid systems, with applications to nuclear fission.

Contribution

It develops novel time-dependent coupled channel equations for pair-breaking, derived from the variational principle, to analyze superfluid dynamics under perturbations.

Findings

Evidence of pair breaking at low excitation energies

Model explains odd-even effects in nuclear fission

Probability calculations for pair states during fission

Abstract

A dynamical pair breaking effect is evidenced at very low excitation energies. For this purpose, a new set of time-dependent coupled channel equations for pair-breaking in superfluid systems are deduced from the variational principle. These equations give the probability to destroy or to create a Cooper pair under the action of some perturbations or when the mean field varies in time. The odd-even effect in fission is investigated within the model as an example. For this purpose, the time-dependent probability to find the system in a seniority-one or in a seniority-two state is restricted in the sense that the perturbations are considered only in the avoided crossing regions.