2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/217080A method to calculate the mean squared matrix element of weak interaction between compound states is developed. The result is expressed in terms of matrix elements of the nucleon-nucleon strong and weak interactions times the Fermi distribution functions at finite temperature. Numerical calculations for $^{233}$Th are in excellent agreement with recent measurements of parity nonconservation effects in neutron capture. In fact, our calculations prove that the factor of dynamical enhancement (ratio of compound-nucleus effect to single-particle one) really exceeds 100, thus making it unnesessary to assume a value of the weak constant bigger than standard one ($g\simeq 10^{8} ε\sim 1÷4$).4 pages, Revtex3, no figuresNuclear Theorytext