Development of shell closures at N=32, 34. II. Lowest yrast excitations in even-even Ti isotopes from deep-inelastic heavy-ion collisions

Abstract

Gamma rays from neutron-rich nuclei in the vicinity of Z=20, N=28 have been studied at Gammasphere using deep-inelastic reactions induced by a 330-MeV 48Ca beam on a thick 238U target. The yrast γ-ray cascade of 56Ti was identified for the first time and the location in energy of the 2+, 4+, and 6+ states was determined. The low-spin 56Ti yrast structure does not support the presence of a subshell closure at N=34 as suggested on the basis of other data on nuclei in the region as well as shell model calculations with a recently proposed interaction.