The effect of the delta resonance on the magnetic dipole properties of the -shell nuclei with has been investigated. When the quark model phasing between the central and tensor transition potentials is used, the delta has little effect on the magnetic moments of the yrast and states. The effect on transition matrix elements is to reduce them by about 6% with some tendency towards a smaller reduction for the lighter nuclei. For seven transitions this quenching improves the agreement between theory and experiment. However, three transitions in the and 12 nuclei already have shell model values which are too small so that the suppression worsens the agreement between theory and experiment. Thus the almost state independent reduction in transition rates predicted when the effect of the delta is included does not resolve some of the discrepancies between calculation and experiment.
- Received 30 January 1984
- Published in the issue dated June 1984
© 1984 The American Physical Society