Contribution of the delta resonance to the Gamow-Teller decay of heavy nuclei

The contribution of the delta isobars to the nuclear beta decay strength function has previously been studied within simple approximation schemes. The effect of the Delta is studied using the charge changing form of the Quasi particle Random Phase Approximation (QRPA) and applied to the Beta decay of neutron deficient tin isotopes Sn-(102 to 110). The principle aim is to address the question of the observed quenching of the low energy positron decay rate of several neutron deficient nuclei. The results of the calculation indicate that the Delta degree of freedom does not affect the low energy distribution of the Beta+/EC strength to such a measure that it would give an important contribution the the quenching. Thus, in the light of the calculation, the question about the role of the Delta can be removed from the discussion.