Parity and time-reversal symmetry nonconservation in neutron-nucleus interactions

摘要

Parity non-conversation was studied for seventeen states in the compound nucleus (sup 239)U by measuring the helicity dependence of the p-wave resonance cross section for epithermal neutrons scattered from (sup 238)U. The root-mean-squared parity-violating matrix element for the mixing of p-wave and s-wave states was determined to be M = 0.58(sub -0.25)(sup +0.50) meV. This corresponds to a parity-violating spreading width of (Gamma)(sup PV) = 1.0 (times) 10(sup (minus)7) eV. This gives a value of 4 (times) 10(sup (minus)7) for (alpha)(sub p), the ratio of strengths of the P-odd and P-even effective nucleon-nucleon interactions in (sup 239)U. The implications of these results for studies of Time Reversal Symmetry in the compound nucleus is discussed.