Quasideuterons in Light Nuclei

TL;DR

This paper investigates the impact of pairing correlations, especially T=0 pairs, on nuclear energies in light nuclei, revealing their maximal formation in N=Z nuclei and their relative robustness compared to T=1 pairing.

Contribution

It provides a detailed analysis of T=0 and T=1 pairing effects on nuclear structure using shell-model calculations, highlighting the significance of quasi-deuteron formation.

Findings

T=0 pairs significantly affect nuclear energies.

Maximal T=0 pairing occurs in N=Z nuclei.

T=0 pairing is less sensitive to single-particle density than T=1 pairing.

Abstract

The role of pairing correlations for nucleon pairs with isospin $T=1$ and $T=0$ is investigated for nuclei in the mass region $12 \leq A \leq 42$. For that purpose the two-nucleon densities resulting from nuclear shell-model calculations in one and two major shells are analyzed. Significant effects on the resulting energies are observed due to the formation of $T=0$ pairs. The formation of quasi-deuterons is maximal for symmetric nuclei with $N=Z$. The formation of $T=0$ pairs is less sensitive to the density of single-particle states close to the Fermi energy than the $T=1$ pairing and is relevant also for excitations across shell-closures. This robustness also explains why $T=0$ pairing does not lead to such a clear evidence in comparing energies of neighbored nuclei as the "odd-even mass staggering" due to the formation of $T=1$ pairing.