ABSOLUTE ALPHA-DECAY WIDTH OF PO-212 IN A COMBINED SHELL AND CLUSTER MODEL

We give a parameter-free microscopic description of the alpha-decay of the ground state of Po-212 by expanding the parent wave function over a basis containing shell-model- as well as cluster-model-type elements. The resulting decay width agrees with experiment well within the range of the uncertainty inherent in the input of the model. The amount of core+alpha clustering in the parent state is found much higher (30%) than former microscopic estimates (approximately 1%), which shows the soundness of assuming the existence of preformed alpha-particles with appreciable probability in the initial state.