Neutron Skin Effects in Mirror Energy Differences: The Case of Mg-23-Na-23

WOS: 000439286800004PubMed: 30085775Energy differences between analogue states in the T = 1/2 Mg-23-Na-23 mirror nuclei have been measured along the rotational yrast bands. This allows us to search for effects arising from isospin-symmetrybreaking interactions (ISB) and/or shape changes. Data are interpreted in the shell model framework following the method successfully applied to nuclei in the f(7/2) shell. It is shown that the introduction of a schematic ISB interaction of the same type of that used in the f(7/2) shell is needed to reproduce the data. An alternative novel description, applied here for the first time, relies on the use of an effective interaction deduced from a realistic charge-dependent chiral nucleon-nucleon potential. This analysis provides two important results: (i) The mirror energy differences give direct insight into the nuclear skin; (ii) the skin changes along the rotational bands are strongly correlated with the difference between the neutron and proton occupations of the s(1/2) "halo" orbit.European Union [262010 ENSAR, FP7/2007-2013]The authors are grateful to the GANIL accelerator team. This work has been financed by the European Union Seventh Framework Program No. FP7/2007-2013 under Grant Agreement No. 262010 ENSAR