Impact of tensor force on quantum shell effects in quasifission reactions

TL;DR

This study uses microscopic TDHF simulations to show that the tensor component of the nucleon-nucleon interaction enhances shell effects, especially at magic neutron number N=126, affecting quasifission dynamics in superheavy element formation.

Contribution

It demonstrates the significant role of the tensor force in dynamical shell effects during quasifission reactions, a novel insight into microscopic nuclear reaction mechanisms.

Findings

Tensor force enhances the prominence of spherical shell effects.

Peak neutron yield aligns with magic number N=126 due to tensor effects.

Dynamical shell effects are influenced by the tensor component of the interaction.

Abstract

Quantum shell effects drive many aspects of many-body quantal systems and their interactions. Among these are the quasifission reactions that impede the formation of a compound nucleus in superheavy element (SHE) searches. Fragment production in quasifission is influenced by shell effects as a nontrivial manifestation of microscopic dynamics hindering the full equilibration of the composite system to form the compound nucleus. In this Letter, we use the microscopic time-dependent Hartree-Fock (TDHF) theory to study 48Ca+249Bk collisions to investigate the influence of the tensor component of the effective nucleon-nucleon interaction. The results show that the inclusion of the tensor force causes the spherical shell effect to become more prominent, particularly for the neutron number yield whose peak is exactly at magic number N = 126. This suggests that the tensor force plays a compelling role in the evolution of dynamical shell effects in nuclear reactions, influencing the competition between spherical and deformed shell gaps.