Beta-decay studies at the N=28 shell closure

Abstract

First results on a β-γ decay spectroscopy experiment of nuclei in the region of N=28 are reported. New β half-lives for nuclei from Mg to Ar have been extracted. For the heavier ones, the new periods of 48 Ar and 47 Cl are of importance in the understanding of solar abundance ratio 48Ca 46Ca . The measured half-lives of Si isotopes have been extended from N=25 to N=28 and are discussed in the light of possible deformation occuring in this region. Finally, preliminary spectroscopy of 45 Ar is also reported.