Low-energy enhancement in the magnetic dipole radiation of actinide nuclei

TL;DR

This paper presents the first theoretical evidence of low-energy enhancement in magnetic dipole gamma-ray strength functions of actinide nuclei, using shell-model Monte Carlo calculations, and compares findings with experimental data.

Contribution

First theoretical demonstration of low-energy enhancement in actinide nuclei's M1 gamma-ray strength functions using SMMC method.

Findings

Low-energy enhancement observed in all six studied actinide nuclei.

Identification of a scissors mode resonance in these nuclei.

Comparison with recent Oslo-method experimental results.

Abstract

We present the first theoretical results of the magnetic dipole (M1) $\gamma$-ray strength function ($\gamma$SF) for actinide nuclei within the shell-model Monte Carlo (SMMC) method. We observe a low-energy enhancement (LEE) in the M1 $\gamma$SFs of the six nuclei studied here, which serves as the first evidence, theoretical or experimental, that the LEE persists in the actinides. We also identify a scissors mode resonance in all six nuclei, which we compare with recent Oslo-method experiments.