Investigation of the pairing effect in 10B nucleus compared with 10Be and 10C nuclei by using the extended THSR wave function

TL;DR

This study uses an extended THSR wave function to analyze nucleon pairing effects in 10B, 10Be, and 10C nuclei, revealing a stronger deuteron-like pairing in 10B and identifying mechanisms behind this phenomenon.

Contribution

The paper introduces a superposed THSR wave function explicitly including pairing configurations, improving energy calculations and revealing enhanced pairing effects in 10B compared to other isotopes.

Findings

Enhanced energy accuracy with the new wave function.

Stronger NN pairing effect observed in 10B.

Identification of mechanisms promoting deuteron-like pairs.

Abstract

In order to study the nucleon-nucleon pairing effects in clustering nuclei, we formulate a superposed Tohsaki-Horiuchi-Schuck-Roepke (THSR) wave function, which includes both molecular-orbit and pairing configurations explicitly. With this new wave function, we investigate the abnormal deuteron-like pn-pairing effect in 10B with T=0 and S=1 (isoscalar) by comparing with isovector NN pairs (T=1, S=1) in 10Be and 10C. Energies are calculated for the ground states of 10Be, 10B and 10C nuclei, and the 1+ excited state of 10B. These energies are essentially improved comparing with studies using previous version of THSR wave function. Further more, overlaps between the total wave function and the pairing component indicate that the NN pairing effect is more visible in 10B than in 10Be and 10C. By analyzing the energies and the overlaps between wave function components, we observe two different mechanisms enhancing the formation of deuteron-like pairs in 10B. We also discuss the pairing effect by showing average distances between components in each nucleus and density distributions of valance nucleons.