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.
Keywords
Cite
@article{arxiv.1903.12219,
title = {Shell evolution approaching the N=20 island of inversion: Structure of 29Mg},
author = {A. Matta and W. N. Catford and N. A. Orr and J. Henderson and P. Ruotsalainen and G. Hackman and A. B. Garnsworthy and F. Delaunay and R. Wilkinson and G. Lotay and Naofumi Tsunoda and Takaharu Otsuka and A. J. Knapton and G. C. Ball and N. Bernier and C. Burbadge and A. Chester and D. S. Cross and S. Cruz and C. Aa. Diget and T. Domingo and T. E. Drake and L. J. Evitts and F. H. Garcia and S. Hallam and E. MacConnachie and M. Moukaddam and D. Muecher and E. Padilla-Rodal and O. Paetkau and J. Park and J. L. Pore and U. Rizwan and J. Smallcombe and J. K. Smith and K. Starosta and C. E. Svensson and J. Williams and M. Williams},
journal= {arXiv preprint arXiv:1903.12219},
year = {2019}
}
Comments
15 pages, 10 figures, 4 tables