Magnetic moments and GT-type β-decay matrix elements in nuclei with a LS doubly closed shell plus or minus one nucleon

Abstract

The magnetic moments and GT-type β-decay matrix elements of nuclei with an 16O core plus (minus) one nucleon and with a 40Ca core plus(minus) one nucleon are studied from the point of view of configuration mixing in terms of second order perturbation theory. It is found that the effect of the mixing of highly excited configurations through a tensor force is essential to explain the large reduction of the GT-type β-decay matrix elements. It is also found that modulus of the isovector parts of the gyromagnetic ratio, g τS and g τl , are appreciably reduced by the configuration mixing.