Three-body model for an isoscalar spin-triplet neutron-proton pair in $^{102}{\rm Sb}$

TL;DR

This paper investigates the isoscalar spin-triplet neutron-proton pairing in $^{102}$Sb using a three-body model with both non-relativistic and relativistic interactions, revealing pair-breaking effects linked to orbital degeneracy.

Contribution

It introduces a three-body model incorporating self-consistent mean-field calculations and compares relativistic and non-relativistic interactions for studying pairing correlations.

Findings

Relativistic interactions better reproduce pseudo-spin symmetry.

Pair-breaking effects are evident in Gamow-Teller transitions.

The $(L,S,T)=(0,1,0)$ pairing scheme is hindered in $^{102}$Sb.

Abstract

We discuss the isoscalar $T=0, S=1$ pairing correlation in the low-lying states of $^{102}{\rm Sb}={}^{100}{\rm Sn}+p+n$ nucleus. To this end, we employ ${\rm core}+p+n$ three-body model with the model space constructed by self-consistent mean-field calculations. The model is developed with both non-relativistic and relativistic effective interactions, the latter of which are found to be more realistic for the present case due to the pseudo-spin symmetry. It turns out that the $(L,S,T)=(0,1,0)$ pairing scheme is strongly hindered in $^{102}$Sb with the relativistic model because of the near degeneracy of the $g_{7/2}$ and $d_{5/2}$ orbitals in the valence space. This pair-breaking effect is clearly seen in the charge-exchange Gamow-Teller-type transitions rather than in the binding energies of $T=0$ and $T=1$ states.