The Nuclear Pairing Gap -- How Low Can It Go?

TL;DR

This paper reports the smallest observed nuclear pairing gap in calcium isotopes, explained through shell model calculations highlighting the influence of shell gaps around specific orbitals.

Contribution

It provides new experimental data on calcium isotopes and offers a theoretical explanation for the minimal pairing gap observed, advancing understanding of nuclear structure.

Findings

Smallest pairing gap observed in $^{53}$Ca.

Shell gaps around the $1p_{1/2}$ orbital influence pairing.

Discussion of minima in pairing gaps across nuclei.

Abstract

The pairing gap for $^{53}$Ca obtained from new experimental data on the masses of $^{52-54}$Ca has the smallest value yet observed. This is explained in the framework of the nuclear shell model with schematic and realistic Hamiltonians as being due to shell gaps around the low-$ j $ orbital $ 1p_{1/2} $. Minima in the pairing gaps for all nuclei are shown and discussed