Evidence of non-statistical neutron emission following beta-decay near doubly magic 132Sn
ORAL
Abstract
It assumed that beta-delayed neutron emission proceeds statistically through the intermediate compound nucleus stage. Neutron emission probabilities from unbound states in 134Sn to known low-lying, single-particle states in 133Sn were measured. Detailed analysis of the neutron-emission branching ratios revealed discrepancies between the statistical model description and data. Our results suggest that a possible violation of the compound nucleus assumption may occur in beta-delayed neutron emission in nearly doubly-magic nuclei. This impacts the neutron emission probabilities and other properties of nuclei participating in the r-process. We propose a revised model of neutron emission, which links the observed neutron emission probabilities to nuclear shell effects using the doorway state concept.
*This research was sponsored in part by the Office of Nuclear Physics, U.S. Department of Energy under Award No. DE-FG02-96ER40983 (UTK) and DEAC05-00OR22725 (ORNL), and by the National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Award No. DE-NA0002132
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Presenters
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Robert Grzywacz
- University of Tennessee
- University of Tennessee and Oak Ridge National Laboratory