Evolution of the ?-ray strength function in neodymium isotopes

Abstract

The experimental gamma-ray strength functions (gamma SFs) of Nd-142,Nd-144-151 have been studied for gamma-ray energies up to the neutron separation energy using the Oslo method. The results represent a unique set of gamma SFs for an isotopic chain with increasing nuclear deformation. The data reveal how the low-energy enhancement, the scissors mode, and the pygmy dipole resonance evolve with nuclear deformation and mass number. This indicates that the mechanisms behind the low-energy enhancement and the scissors mode are decoupled from each other.