Deformation from zinc to zirconium

TL;DR

This paper investigates nuclear deformation in neutron-rich isotopes of Ni and Sn using gamma-ray spectroscopy, revealing persistent deformation beyond N=60 and shell erosion near 78Ni, with theoretical modeling of collective effects.

Contribution

It provides new experimental data on deformation and shell erosion in neutron-rich nuclei, and discusses the application of the projected generator coordinate method for these isotopes.

Findings

Persistence of deformation beyond N=60

Erosion of N=50 shell closure near 78Ni

Evidence of collective effects in neutron-rich isotopes

Abstract

Extensive gamma-ray spectroscopy of very neutron-rich nuclei of isotopes between the Ni and Sn isotopic chains was facilitated by the high luminosity LH2 target system, MINOS. Results show a persistence of deformation when going beyond the N = 60 threshold of the transition between spherical to deformed ground states at N < 60 and N > 60, respectively. Close to 78Ni, a more detailed image of the N > 50 Zn isotopes shows an erosion of the N = 50 shell closure, with core-breaking effects needed from theoretical models to replicate observation. As well as the experimental results indicating collective effects, the projected generator coordinate method is discussed in detail within the context of the neutron-rich Ge isotopes.