Target Mass Corrections in Diffractive Scattering

We describe the twist-2 contributions to inclusive unpolarized and polarized deep-inelastic diffractive scattering in an operator approach. The representation refers to the observed large rapidity gap but does not require reference to a pomeron picture. We discuss both the case of vanishing target mass $M$ and momentum transfer $t$ as well as the effects at finite $t$ and $M$, which lead to modifications at large $\beta$ and low values of $Q^2$.