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Statistical Theory of Parity Nonconservation in Compound Nuclei

S. Tomsovic·Mikkel B. Johnson·A. Hayes·J. D. Bowman
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Abstract

We present the first application of statistical spectroscopy to study the root-mean-square value of the parity nonconserving (PNC) interaction matrix element M determined experimentally by scattering longitudinally polarized neutrons from compound nuclei. Our effective PNC interaction consists of a standard two-body meson-exchange piece and a doorway term to account for spin-flip excitations. Strength functions are calculated using realistic single-particle energies and a residual strong interaction adjusted to fit the experimental density of states for the targets, ^{238} U for A\sim 230 and ^{104,105,106,108} Pd for A\sim 100. Using the standard Desplanques, Donoghue, and Holstein estimates of the weak PNC meson-nucleon coupling constants, we find that M is about a factor of 3 smaller than the experimental value for ^{238} U and about a factor of 1.7 smaller for Pd. The significance of this result for refining the empirical determination of the weak coupling constants is discussed.

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S. Tomsovic, Mikkel B. Johnson, A. Hayes, J. D. Bowman. 2000-09-27. Statistical Theory of Parity Nonconservation in Compound Nuclei. https://doi.org/10.1103/physrevc.62.054607

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