MODEL FOR RESONANCE ENHANCEMENT OF P- AND T-NONINVARIANT EFFECTS IN NEUTRON REACTIONS

摘要

We consider the effects of P- and possible P-,T-violation in resonant neutron-nucleus interaction in the model with coupled channels. An analytical description of neutron resonance with arbitrary orbital momentum is given when two coupled channels are taken into account. A case of a weak channel coupling, corresponding to narrow resonance, is analyzed in details. A deviation of the resonance amplitudes from Breit-Wigner form is investigated. As far as the total width of the resonance coincides with the neutron one, the model is directly appropriate only for light nuclei. We study a mixing of two narrow s- and p-wave resonances by P- and P-,T-noninvariant potentials in the first order of perturbation theory. As an example a close-lying pair of s- and p-wave resonances of the Cl-35 nucleus is considered. An explicit expression for the resonance enhancement factor of mixing amplitude is derived. Ln the resonance with an orbital momentum l it is found to be similar to (omega/gamma(l))(1/2)(1/(kR)(2l+1)), where omega is a characteristic single-particle energy and yi is a reduced width of the resonance. The favorable possibilities are shown to exist for measurements not only in resonances, but beyond them as well. [References: 47]