In-beam γ -ray spectroscopy of S 38 – 42

The low-energy excitation level schemes of the neutron-rich S38-42 isotopes are investigated via in-beam gamma-ray spectroscopy following the fragmentation of Ca-48 and Ar-46 projectiles on a C-12 target at intermediate beam energies. Information on gamma gamma coincidences complemented by comparisons to shell-model calculations were used to construct level schemes for these neutron-rich nuclei. The experimental data are discussed in the context of large-scale shell-model calculations with the SDPF-MU effective interaction in the sd-pf shell. For the even-mass S isotopes, the evolution of the yrast sequence is explored as well as a peculiar change in decay pattern of the second 2(+) states at N = 26. For the odd-mass S-41, a level scheme is presented that seems complete below 2.2 MeV and consistent with the predictions by the SDPF-MU shell-model Hamiltonian; this is a remarkable benchmark given the rapid shell and shape evolution at play in the S isotopes as the broken-down N = 28 magic number is approached. Furthermore, the population of excited final states in projectile fragmentation is discussed.