Effect of proton-proton Coulomb repulsion on soft dipole excitations of light proton-rich nuclei

TL;DR

This study models soft dipole excitations in the proton-rich nucleus $^{17}$Ne, demonstrating that Coulomb repulsion between valence protons has minimal impact on E1 strength distribution and can be effectively simulated by adjusting nuclear pairing interactions.

Contribution

It introduces a three-body model calculation for $^{17}$Ne that explicitly includes Coulomb effects, showing they can be approximated by renormalizing the pairing interaction.

Findings

Coulomb repulsion does not significantly change the E1 strength distribution.

Coulomb effects can be simulated by renormalizing the nuclear pairing interaction.

The model successfully describes soft dipole excitations in $^{17}$Ne.

Abstract

We perform three-body model calculations for soft dipole excitations of the proton-rich Borromean nucleus $^{17}$Ne. To this end, we assume that $^{17}$Ne takes the $^{15}$O+p+p structure, in which the two valence protons are excited from the $0^+$ ground state configuration to $1^-$ continuum states. We employ a density-dependent contact force for the nuclear part of the pairing interaction, and discretize the continuum states with the box boundary condition. We show by explicitly including the Coulomb interaction between the valence protons that the Coulomb repulsion does not significantly alter the E1 strength distribution. We point out that the effect of the Coulomb repulsion in fact can be well simulated by renormalizing the nuclear pairing interaction.