Effect of ground-state deformation on the Isoscalar Giant Monopole Resonance and the first observation of overtones of the Isoscalar Giant Quadrupole Resonance in rare-earth Nd isotopes

TL;DR

This study investigates how ground-state deformation affects the ISGMR and ISGQR in Nd isotopes, revealing resonance splitting, and reports the first observation of overtones in ISGQR at around 25 MeV.

Contribution

It provides the first detection of overtones in ISGQR and analyzes the impact of nuclear deformation on resonance splitting in Nd isotopes.

Findings

ISGMR strength splits in deformed nuclei

Single peak in spherical 142Nd

First observation of ISGQR overtones at ~25 MeV

Abstract

The strength distributions of the Isoscalar Giant Monopole Resonance (ISGMR) and Isoscalar Giant Quadrupole Resonance (ISGQR) in 142,146-150Nd have been determined via inelastic alpha-particle scattering with the Grand Raiden (GR) Spectrometer at the Research Center for Nuclear Physics (RCNP), Japan. In the deformed nuclei 146-150Nd, the ISGMR strength distributions exhibit a splitting into two components, while the nearly spherical nucleus 142Nd displays a single peak in the ISGMR strength distribution. A noteworthy achievement in this study is the first-time detection of overtones in the Isoscalar Giant Quadrupole Resonance (ISGQR) strength distributions within Nd isotopes at an excitation energy around 25 MeV obtained through Multipole Decomposition Analysis (MDA).