Average over energy effect of parity nonconservation in neutron scattering on heavy nuclei

Using semiclassical approximation we consider parity nonconservation (PNC) averaged over compound resonances. We demonstrate that the result of the averaging crucially depends on the properties of residual strong nucleon-nucleon interaction. Natural way to elucidate this problem is to investigate experimentally PNC spin rotation with nonmonachromatic neutron beam: $E \sim \Delta E \sim 1MeV$. Value of the effect can reach $\psi \sim 10^{-5}-10^{-4}$ per mean free path.