We calculate the average helicity dependence of the low-energy neutron-nucleus cross section in terms of a phenomenological optical model. Comparison with recent measurements on Th232 and U238 by the TRIPLE Collaboration shows that the effective parity-nonconserving interaction is two orders of magnitude larger than estimates based on standard meson-exchange models. The helicity dependence is predicted to oscillate with target mass due to shape resonances.
ASJC Scopus subject areas
- Physics and Astronomy(all)