In-beam gamma-ray spectroscopy of very neutron-rich nuclei: Excited states in 46S and 48Ar

TL;DR

This study investigates the excited states of very neutron-rich nuclei 46S and 48Ar using in-beam gamma-ray spectroscopy, involving novel production methods and shell-model comparisons to understand their nuclear structure.

Contribution

First in-beam gamma-ray spectroscopy of 46S, employing a novel two-step production method involving nucleon exchange and neutron pickup reactions.

Findings

Identification of excited states in 46S and 48Ar

Comparison with shell-model calculations shows good agreement

Provides insights into the structure of neutron-rich sdpf-shell nuclei

Abstract

We report on the first in-beam gamma-ray spectroscopy study of the very neutron-rich nucleus 46S. The N=30 isotones 46S and 48Ar were produced in a novel way in two steps that both necessarily involve nucleon exchange and neutron pickup reactions, 9Be(48Ca,48K)X followed by 9Be(48K,48Ar+gamma)X at 85.7 MeV/u mid-target energy and 9Be(48Ca,46Cl)X followed by 9Be(46Cl,46S+gamma)X at 87.0 MeV/u mid-target energy, respectively. The results are compared to large-scale shell-model calculations in the sdpf shell using the SDPF-NR effective interaction and Z-dependent modifications.