Abstract
The low-lying level structures of nuclei in the vicinity of were investigated using in-beam -ray spectroscopy to clarify the nature of the nuclear magic numbers and in systems close to the neutron drip line. Nucleon knockout reactions were employed to populate excited states in and . A candidate for the level in was identified at 1979(30) keV, and the lifetime of this state was estimated to be ps from a line-shape analysis. Moreover, the energy of the state in is reported to lie at 621(11) keV. The large drop in the energy at indicates the presence of a significant peak in the systematics at . Furthermore, the and ratios in were deduced to be and , respectively. These results imply that can be described in terms of two-proton configurations with a core and are consistent with a robust magic number along the Zn isotopic chain. These observations, therefore, indicate a persistent shell closure in nuclei far from the line of stability, which in turn suggests a doubly magic structure for .
- Received 20 November 2015
DOI:https://doi.org/10.1103/PhysRevC.93.024320
©2016 American Physical Society