Structure of <SUP>28</SUP>Mg and influence of the neutron <i>pf</i> shell



Williams, J, Ball, GC, Chester, A, Domingo, T, Garnsworthy, AB, Hackman, G, Henderson, J, Henderson, R, Krucken, R, Kumar, Anil
et al (show 11 more authors) (2019) Structure of <SUP>28</SUP>Mg and influence of the neutron <i>pf</i> shell. PHYSICAL REVIEW C, 100 (1). 014322-.

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Abstract

Gamma-ray spectroscopy and lifetime measurements using the Doppler shift attenuation method (DSAM) were performed on the nucleus Mg28 near the N=20 "island of inversion," which was populated using a C12(O18,2p)Mg28 fusion-evaporation reaction to investigate the impact of shell evolution on its high-lying structure. Three new levels were identified at 7203(3), 7747(2), and 7929.3(12) keV along with several new gamma rays. A newly extracted B(E2;41+→21+) of 42(7) e2fm4 indicates reduced collectivity in the yrast band at high spin, consistent with ab initio symmetry adapted no-core shell model (SA-NCSM) calculations. At high excitation energy, evidence for the population of intruder orbitals was obtained through identification of negative parity levels [Iπ=(0,4)-, (4,5)-]. Calculations using the SDPF-MU interaction indicate that these levels arise from single neutron excitation to the pf shell and provides evidence for the lowering of these intruder orbitals approaching the island of inversion.

Item Type: Article
Depositing User: Symplectic Admin
Date Deposited: 05 Dec 2019 17:42
Last Modified: 17 Mar 2024 05:00
DOI: 10.1103/PhysRevC.100.014322
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3065050