Effect of isoscalar spin-triplet pairings on spin-isospin responses in $sd-$ shell nuclei

TL;DR

This paper investigates how isoscalar spin-triplet pairing correlations affect spin magnetic dipole transitions and neutron-proton spin-spin correlations in sd-shell nuclei, revealing significant quenching effects and the influence of resonance-hole coupling.

Contribution

It demonstrates the substantial impact of isoscalar spin-triplet pairing on spin responses and correlations in sd-shell nuclei, incorporating resonance-hole coupling effects.

Findings

Isoscalar spin-triplet pairing causes quenching of spin magnetic dipole transitions.

Enhanced pairing influences proton-neutron spin-spin correlations.

Resonance-hole coupling affects IV spin transitions and ground state correlations.

Abstract

The spin magnetic dipole transitions and the neutron-proton spin-spin correlations in $sd-$shell even-even nuclei with $N=Z$ are investigated using shell model wave functions. The isoscalar spin-triplet pairing correlation provides a substantial quenching effect on the spin magnetic dipole transitions, especially the isovector (IV) ones. Consequently, an enhanced isoscalar spin-triplet pairing interaction influences the proton-neutron spin-spin correlation deduced from the difference between the isoscalar (IS) and the IV sum rule strengths. The effect of the $\Delta$ ($\Delta_{33}$ resonance)-hole coupling is examined in the IV spin transition and the spin-spin correlations of the ground states.