Spin Effects in High Energy Photon-Hadron Scattering in QCD

Abstract

The spin effects at high energies and momenta transferred $|t|>1Ge{V}^2$ are analysed for quark-photon scattering. The energy independence of the ratio of spin-flip and spin-non-flip amplitudes in the same ${\alpha }_s$ order of QCD is obtained. It is shown that the contribution of the spin-dependent quark-pomeron vertex to the spin-flip amplitude is intensified by off-mass-shell effects in the quark loop. As a result, the magnitude of this amplitude can reach 20-30\% from a spin-non-flip one. The dependence of the cross-section on the form-factor and ${\alpha }_s^3$ spin-non-flip contributions are observed.

Comments: 9 pages, LaTex, 4 Figures (not encluded, avalable from the authors), JINR Preprint E2-94-348, Dubna,1994