Low-energy enhancement of the magnetic dipole radiation in odd-mass lanthanides

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: DeMartini, D., Alhassid, Y.
Formato: Preprint
Publicado: 2024
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866912270115667968
author DeMartini, D.
Alhassid, Y.
author_facet DeMartini, D.
Alhassid, Y.
contents We compute the magnetic dipole (M1) $γ$-ray strength functions ($γ$SF) for the odd-mass lanthanides $^{143-151}$Nd and $^{147-153}$Sm using the shell-model Monte Carlo method in combination with the static-path approximation and the maximum-entropy method. In particular, we quantify the statistical uncertainties in the calculated M1 $γ$SFs and show that they are under control for the excitation energies relevant to the experiments despite a Monte Carlo sign problem that originates in the projection onto an odd number of neutrons. We identify a low-energy enhancement (LEE) in the M1 $γ$SFs of these odd-mass lanthanides, which was recently observed experimentally in some of them. We also find a scissors mode resonance (SR) in the strongly deformed isotopes. We observe that the decrease in the LEE strength with neutron number along an isotopic chain is compensated for by an increase in the SR strength in the deformed nuclei. We compare our results with recent experiments.
format Preprint
id arxiv_https___arxiv_org_abs_2410_00109
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Low-energy enhancement of the magnetic dipole radiation in odd-mass lanthanides
DeMartini, D.
Alhassid, Y.
Nuclear Theory
We compute the magnetic dipole (M1) $γ$-ray strength functions ($γ$SF) for the odd-mass lanthanides $^{143-151}$Nd and $^{147-153}$Sm using the shell-model Monte Carlo method in combination with the static-path approximation and the maximum-entropy method. In particular, we quantify the statistical uncertainties in the calculated M1 $γ$SFs and show that they are under control for the excitation energies relevant to the experiments despite a Monte Carlo sign problem that originates in the projection onto an odd number of neutrons. We identify a low-energy enhancement (LEE) in the M1 $γ$SFs of these odd-mass lanthanides, which was recently observed experimentally in some of them. We also find a scissors mode resonance (SR) in the strongly deformed isotopes. We observe that the decrease in the LEE strength with neutron number along an isotopic chain is compensated for by an increase in the SR strength in the deformed nuclei. We compare our results with recent experiments.
title Low-energy enhancement of the magnetic dipole radiation in odd-mass lanthanides
topic Nuclear Theory
url https://arxiv.org/abs/2410.00109