Analyzing-power and cross-section fluctuations in nuclear reactions with the spin structure 1/2+J1 J2J3

On the basis of the statistics of the fluctuating part of the S matrix we study fluctuations of the differential analyzing power and the differential cross section in nuclear reactions 1/2+J1 J2J3 in the case of a strong overlap of resonance levels. It is shown that the simultaneous investigation of fluctuations of the analyzing power and of the cross section makes it possible to separate contributions from the direct and compound-nucleus mechanisms to the cross section for the reaction and to determine spins of nuclear levels and the polarization of the incident beam. The study of the statistical correlation between the analyzing power and the cross section is performed on the basis of functions of their common probability distribution. The strength of the correlation is proportional to the contribution from direct processes to the reaction cross section and it vanishes in the case of purely a statistical mechanism of the interaction. The effect of statistical correlation permits the test of initial assumptions of the fluctuation theory of nuclear reactions and serves also as a test of exposure of intermediate structure in the reaction. The results are used in the analysis of inelastic polarized-proton scattering by SYSi. The comparison with experimentmore » supports the existence of a statistical correlation between the fluctuations of the analyzing power and of the cross section.« less