On l-forbidden M1 transitions

Abstract

An analysis of l-forbidden M1 transitions has been carried out. Seven transitions for which the lifetime, conversion co-efficient and E2/M1 mixing ratio are experimentally known, have been considered. The M1 transition probabilities show retardations (compared to single-particle estimates) ranging from 37 to 920, whereas the reduced E2 transition probabilities show enhancements ranging from 6 to 17. While configuration mixing can qualitatively explain the M1 matrix elements, the E2 enhancements clearly imply a collective type of behaviour. However, the surface tension parameters calculated on the basis of the weak coupling model appear to be unreasonably large in some cases considered.