Identification of the crossing point at N=21 between normal and intruder configurations



Lica, R, Rotaru, F, Borge, MJG, Grevy, S, Negoita, F, Poves, A, Sorlin, O, Andreyev, AN, Borcea, R, Costache, C
et al (show 29 more authors) (2017) Identification of the crossing point at N=21 between normal and intruder configurations. PHYSICAL REVIEW C, 95 (2).

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Abstract

The β- decay of Mg34 was used to study the Al34 nucleus through γ spectroscopy at the Isotope Separator On-Line facility of CERN. Previous studies identified two β-decaying states in Al34 having spin-parity assignments Jπ=4- dominated by the normal configuration π(d5/2)-1 - ν(f7/2) and Jπ=1+ by the intruder configuration π(d5/2)-1 - ν(d3/2)-1(f7/2)2. Their unknown ordering and relative energy have been the subject of debate for the placement of Al34 inside or outside the N=20 "island of inversion." We report here that the 1+ intruder lies only 46.6 keV above the 4- ground state. In addition, a new half-life of T1/2=44.9(4)ms, that is twice as long as the previously measured 20(10) ms, has been determined for Mg34. Large-scale shell-model calculations with the recently developed sdpf-u-mix interaction are compared with the new data and used to interpret the mechanisms at play at the very border of the N=20 island of inversion.

Item Type: Article
Depositing User: Symplectic Admin
Date Deposited: 04 Apr 2017 09:19
Last Modified: 19 Jan 2023 07:09
DOI: 10.1103/PhysRevC.95.021301
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3006587