Pair production of squarks in ep-collisions

The production of squarks et ep colliders is studied by comparing the Weizsaecker-Williams approximation and an exact tree level calculation. We consider the process ep→eq tilde q tildeX→eqq tilde γ tilde γ tilde. For this calculation, on the amplitude level, the Feynman diagrams can be split into sub-diagrams. This splitting has great advantages for numerical calculations. Using these techniques the dependence of the cross section on the mass of the squark is computed. We also present various kinematical distributions. An elegant method for calculating tree amplitudes with external fermions of arbitrary mass and spin is given for completeness. (orig.)