Twist-three observables in deeply virtual Compton scattering on the nucleon

Zusammenfassung

We study twist-three effects in deeply virtual Compton scattering on an unpolarized spin-1/2 target. A careful definition of observables as Fourier moments w.r.t. the azimuthal angle allows for a clear separation of twist-two and -three effects. Although the latter are power suppressed, they give leading contributions to the twist-three asymmetries and do not affect the twist-two observables. (C) 2001 Published by Elsevier Science B.V.