Microscopic Description of Isoscalar Giant Monopole Resonance in $^{48}$Ca

TL;DR

This paper presents a microscopic model for analyzing the isoscalar giant monopole resonance in $^{48}$Ca, incorporating complex phonon couplings to better describe its energy distribution and width.

Contribution

It introduces a novel method for including one-, two-, and three-phonon couplings in the wave functions of $0^{+}$ states within a Skyrme-based framework.

Findings

Three-phonon configurations redistribute ISGMR strength to lower and higher energies.

The approach effectively describes the gross structure of ISGMR spreading width.

Results align with experimental observations of $^{48}$Ca's monopole resonance.

Abstract

The properties of the isoscalar giant monopole resonance (ISGMR) for the double magic $^{48}$Ca are analyzed in the framework of a microscopic model based on Skyrme-type interactions. A method for simultaneously taking into account the coupling between one-, two-, and three-phonon terms in the wave functions of $0^{+}$ states has been developed. The inclusion of three-phonon configurations leads to a substantial redistribution of the ISGMR strength to lower energy $0^{+}$ states and also higher energy tail. Our results demonstrate that the developed approach enables to us to describe a gross structure of the ISGMR spreading width.