  In this work, we will evaluate the nucleon helicity flip form factor at the
limit of large momentum transfer. Hereby, we will study the exchange of one and
two virtual photons separately. For the calculation of the scattering
amplitudes and nucleon transition probability matrix elements, we combine QCD
perturbation theory with an expansion in nucleon distribution amplitudes. Using
the combination of leading and sub-leading twist nucleon distribution
amplitudes, one obtains the desired form factor. Using this technique, we will
obtain a divergent result for the form factor. Nevertheless, the structure of
the divergency can be extracted. Finally, we will comment the obtained
expressions and discuss the behavior in unpolarized and polarized cross
sections.

High Energy Physics - Phenomenology