Alpha Decay Width of212Po from a quartetting wave function approach

Abstract

An effective α particle equation is derived for cases where an α particle is bound to a doubly magic nucleus. As an example, we consider212Po with the α on top of the208Pb core. The fully quantal solution of the problem is inspired by the THSR (Tohsaki-Horiuchi-Schuck-Röpke) wave function concept that has been successfully applied to light nuclei. Shell model calculations are improved by including four-particle (α-like) correlations that are of relevance when the matter density becomes low. In the region where the α-like cluster penetrates the core nucleus, the intrinsic bound state wave function transforms at a critical density into an unbound four-nucleon shell model state. We present a microscopic calculation of both α-cluster preformation probability and decay width in typical α-emitter212Po. Using actually measured density distribution of the208 Pb core, the calculated alpha decay width of212Po agrees fairly well with the measured one. Applications to other nuclei (20Ne) are discussed.