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arXiv · 2401.00591

Magnetic dipole $\gamma$-ray strength functions of heavy nuclei in the configuration-interaction shell model

Y. Alhassid·P. Fanto·A. Mercenne
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Abstract

A low-energy enhancement (LEE) has been observed in the deexcitation $\gamma$-ray strength function ($\gamma$SF) of compound nuclei. The LEE has been a subject of intense experimental and theoretical interest since its discovery, and, if the LEE persists in heavy neutron-rich nuclei, it would have significant effects on calculations of r-process nucleosynthesis. Standard configuration-interaction (CI) shell-model calculations in medium-mass nuclei have attributed the LEE to the magnetic dipole $\gamma$SF but such calculations are computationally intractable in heavy nuclei. We review a combination of beyond-mean-field many-body methods within the framework of the CI shell model that enables the calculation of $\gamma$SF in heavy nuclei, and discuss the recent theoretical identification of a LEE in the magnetic dipole $\gamma$SF of lanthanide isotopes.

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Y. Alhassid, P. Fanto, A. Mercenne. 2023-12-31. Magnetic dipole $\gamma$-ray strength functions of heavy nuclei in the configuration-interaction shell model. https://arxiv.org/abs/2401.00591

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