Collectivity at N=50: 82Ge and 84Se

TL;DR

This study investigates the nuclear structure of neutron-rich isotones 82Ge and 84Se near N=50, revealing differences in excited state populations through Coulomb excitation and inelastic scattering, and comparing results with shell-model predictions.

Contribution

It provides new experimental data on excited states of 82Ge and 84Se and compares these with shell-model calculations using multiple effective interactions.

Findings

Strong 4+ state population in 84Se during inelastic scattering.

Limited excitation of higher states in 82Ge under Coulomb excitation.

Differences in nuclear response between 82Ge and 84Se explained by shell-model analysis.

Abstract

The neutron-rich N=50 isotones 82Ge and 84Se were investigated using intermediate-energy Coulomb excitation on a 197Au target and inelastic scattering on 9Be. As typical for intermediate-energy Coulomb excitation with projectile energies exceeding 70 MeV/nucleon, only the first 2^+ states were excited in 82Ge and 84Se. However, in the inelastic scattering on a 9Be target, a strong population of the first 4^+ state was observed for 84Se, while there is no indication of a similarly strong excitation of the corresponding state in the neighboring even-even isotone 82Ge. The results are discussed in the framework of systematics and shell-model calculations using three different effective interactions.