Ternary quasifission in collisions of actinide nuclei

TL;DR

This study uses time-dependent covariant density functional theory to explore ternary quasifission in uranium-238 collisions, revealing how nuclear shape degrees of freedom and pairing correlations influence fragment formation and energy windows.

Contribution

It introduces a detailed microscopic analysis of ternary quasifission in actinide collisions, highlighting the roles of octupole deformation and pairing correlations.

Findings

Octupole deformation extends the energy window for ternary quasifission.

Pairing correlations suppress ternary quasifission in head-to-head collisions.

Formation of heavy neutron-rich systems is predicted in specific energy ranges.

Abstract

The microscopic framework of time-dependent covariant density functional theory is applied to a systematic study of ternary quasifission in collisions of pairs of $^{238}$U nuclei. It is shown that the inclusion of octupole degree of freedom in the case of head-to-head collisions, extends the energy window in which ternary quasifission occurs, and greatly enhances the number of nucleons contained in a middle fragment. Dynamical pairing correlations, included here in the time-dependent BCS approximation, prevent the occurrence of ternary quasifission in head-to-head collisions, and have an effect on the location of the energy window in which a middle fragment is formed in tail-to-tail collisions. In the latter case, as well as for tail-to-side collisions, the formation of very heavy neutron-rich systems in certain energy intervals is predicted.