Fine structure of the isoscalar giant monopole resonance in $^{48}$Ca

TL;DR

This paper investigates the fine structure of the isoscalar giant monopole resonance in calcium-48 using high-resolution alpha scattering experiments and compares the results with advanced theoretical models, revealing good agreement.

Contribution

It provides detailed experimental data on the ISGMR in 48Ca and compares it with state-of-the-art Skyrme-RPA calculations including phonon-phonon coupling, enhancing understanding of nuclear resonance structures.

Findings

Observation of considerable fine structure in the ISGMR of 48Ca.

Extraction of characteristic energy scales via wavelet analysis.

Good agreement between experimental data and advanced theoretical models.

Abstract

Experiments investigating the fine structure of the IsoScalar Giant Monopole Resonance (ISGMR) of 48Ca were carried out with a 200 MeV alpha inelastic-scattering reaction, using the high energy-resolution capability and the zero-degree setup at the K600 magnetic spectrometer of iThemba LABS, Cape Town, South Africa. Considerable fine structure is observed in the energy region of the ISGMR. Characteristic energy scales are extracted from the experimental data by means of a wavelet analysis and compared with the state-of-the-art theoretical calculations within a Skyrme-RPA (random phase approximation) approach using the finite-rank separable approximation with the inclusion of phonon-phonon coupling (PPC). Good agreement was observed between the experimental data and the theoretical predictions.