Radiative strength functions in 163,164Dy

TL;DR

This study investigates the radiative strength functions of 163,164Dy nuclei using the Oslo method, revealing a pygmy M1 resonance and enhanced gamma strength above 5 MeV, with comparisons to previous data on dysprosium isotopes.

Contribution

First application of the Oslo method to 163,164Dy nuclei for extracting radiative strength functions and identifying a pygmy M1 resonance in these isotopes.

Findings

Identification of a pygmy M1 resonance around 3 MeV in both nuclei.

Observation of enhanced gamma strength above 5 MeV in 164Dy.

Comparison of resonance parameters with previous dysprosium isotope data.

Abstract

The nuclei 163,164Dy have been investigated using the Oslo method on data from the pick-up reaction 164Dy(3He,alpha gamma)163Dy and the inelastic scattering 164Dy(3He,3He' gamma)164Dy, respectively. The radiative strength functions for both nuclei have been extracted, and a small resonance centered around Eg ?3 MeV is observed in both cases. The parameters of this so-called pygmy M1 resonance (the scissors mode) are compared to previous results on 160,161,162Dy using the Oslo method, and to data on 163Dy measured by the Prague group using the two-step cascade method. In particular, the integrated reduced transition probability B(M1) of the pygmy resonance is compared with neighboring dysprosium isotopes. We also observe an enhanced strength in the region above gamma energy around 5 MeV in 164Dy. Possible origins of this feature are discussed.