Parity mixing in 19F and the weak parity non-conserving nucleon-nucleon interaction

We report calculations of the asymmetry of the 110 keV photon emitted in the decay of the polarized $\text{1}\text{2}$^? first excited state of ¹⁹F. The calculations employ short range correlations obtained by solving the Bethe-Goldstone equation in the A = 20 system, and are carried out for a wide range of weak parity non-conserving potentials suggested in the literature. Because of the large experimental error of the observed asymmetry, many of these potentials give results compatible with the experimental value. A calculation of the parity allowed E1 matrix element suggests that the standard Cabibbo potential gives results which disagree in sign with the observed asymmetry, which has also been the case in other parity non-conserving transitions.