Al. Barabanov, MODEL FOR RESONANCE ENHANCEMENT OF P-NONINVARIANT AND T-NONINVARIANT EFFECTS IN NEUTRON REACTIONS, Nuclear physics. A, 614(1), 1997, pp. 1-43
We consider the effects of P- and possible P-,T-violation in resonant
neutron-nucleus interaction in the model with coupled channels. An ana
lytical description of neutron resonance with arbitrary orbital moment
um is given when two coupled channels are taken into account. A case o
f a weak channel coupling, corresponding to narrow resonance, is analy
zed in details. A deviation of the resonance amplitudes from Breit-Wig
ner form is investigated. As far as the total width of the resonance c
oincides with the neutron one, the model is directly appropriate only
for light nuclei. We study a mixing of two narrow s- and p-wave resona
nces by P- and P-,T-noninvariant potentials in the first order of pert
urbation theory. As an example a close-lying pair of s- and p-wave res
onances of the Cl-35 nucleus is considered. An explicit expression for
the resonance enhancement factor of mixing amplitude is derived. Ln t
he 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 si
ngle-particle energy and yi is a reduced width of the resonance. The f
avorable possibilities are shown to exist for measurements not only in
resonances, but beyond them as well.