Aligned neutron--proton pairs in $N\sim Z$ nuclei

TL;DR

This paper proposes a new interpretation of certain $N ext{~} ext{Z}$ nuclei using aligned neutron-proton pairs with high angular momentum, formulating an isoscalar boson model and applying it to a specific isomer.

Contribution

It introduces a novel interacting boson model based on isoscalar high-spin bosons for $N ext{~} ext{Z}$ nuclei with $90 ext{~}A ext{~}100$, demonstrating its application to a $^{94}$Ag isomer.

Findings

Model successfully describes the $21^+$ isomer in $^{94}$Ag.

Aligned neutron-proton pairs are key to understanding structure in $N ext{~} ext{Z}$ nuclei.

Provides a new theoretical framework for high-spin states in these nuclei.

Abstract

It is argued that $N\sim Z$ nuclei with $90\leq A\leq100$ can be interpreted in terms of aligned neutron--proton pairs with angular momentum $J=2j$ and isospin T=0. Based on this observation, a version of the interacting boson model is formulated in terms of isoscalar high-spin bosons. To illustrate its possible use, the model is applied to the $21^+$ isomer in $^{94}$Ag.