Parity nonconservation in (n,p) photocapture at thermal energy; the influence of strong and weak interactions

Details are presented of extensive calculations of the manifestations of parity nonconservation in the capture of thermal neutrons. For any weak interaction theory heretofore proposed the resulting values of the circular polarisation of the 2.2 MeV photon differ from the experimental results of Lobashov et al. by two orders of magnitude, independently of the choice of description of n-p short-range correlations. A phenomenolical approach to the weak interaction potential which is able to give the circular polarization seen by Lobashov, is suggested and its consequences discussed. (Auth.)