Parity violation in the compound nucleus: The role of distant states

Abstract

We explain why the measured parity-violating asymmetries for ${\mathit{p}}_{1/2}$ compound-nuclear resonances tend to have a common sign. We show that the asymmetry is a sum of two terms: a' average term dominated by admixtures of distant levels and a term that fluctuates from resonance to resonance dominated by admixtures of nearby compound-nuclear states. The average asymmetry involves single-particle transition amplitudes of the parity-violating interaction, while the fluctuating asymmetry retains a statistical character. Our theoretical estimate of the average asymmetry agrees with a value extracted from experimental data.