Shell evolution approaching the N=20 island of inversion: Structure of 29Mg

Abstract

The "Island of Inversion" for neutron-rich nuclei in the vicinity of N=20 has become the testing ground par excellence for our understanding and modelling of shell evolution with isospin. In this context, the structure of the transitional nucleus 29Mg is critical. The first quantitative measurements of the single particle structure of 29Mg are reported, using data from the d(28Mg,p gamma)29Mg reaction. Two key states carrying significant ell=3 (f-wave) strength were identified at 2.40 +/- 0.10 (Jpi = 5/2-) and 4.28 +/- 0.04 MeV (7/2-). New state-of-the-art shell model calculations have been performed and the predictions are compared in detail with the experimental results. Whilst the two lowest 7/2- levels are well described, the sharing of single-particle strength disagrees with experiment for both the 3/2- and 5/2- levels and there appear to be general problems with configurations involving the p3/2 neutron orbital and core-excited components. These conclusions are supported by an analysis of the neutron occupancies in the shell model calculations.

15 pages, 10 figures, 4 tables

References in corpus (2)

• Nuclear magic numbers: new features far from stability
• Systematics of intermediate-energy single-nucleon removal cross sections

Cited by in corpus (4)

• Experimental study of intruder components in light neutron-rich nuclei via single-nucleon transfer reaction
• Border of the Island of Inversion: Unbound states in ${}^{29}$Ne
• Single neutron transfer on 23Ne and its relevance forthepathway ofnucleosynthesis in astrophysical X-ray bursts
• Ab initio study of island of inversion in odd-$A$ nuclei: Structure of ${}^{31,33}$Mg