Supersymmetry searches at electron-proton colliders

At the moment, in high energy physics there exists a very successful model, 'the Standard Model', which describes with high accuracy all available data on strong, weak and electro-magnetic interactions. The Standard Model is accepted to be a theory predictive up to a certain energy scale. Beyond this scale the Standard model becomes part of a more fundamental theory. The simplest supersymmetric extension of the Standard Model, the Minimal Supersymmetric Standard Model, contains all particles of the Standard Model with the familiar leptons, quarks and gauge bosons, together with their new supersymmetric partners, the spin-0 sleptons and squarks and the spin-1/2 gauginos. In chapter 1, the motivation for a Supersymmetric Standard Model at the intermediate scale is given. Also the general ideas of supersymmetry are explained, and a description of the Minimal Supersymmetric Standard Model is given. In chapter 2, the production of a squark pair in ep-collisions is studied. The calculations, for HERA, a possible upgrade for HERA and the LEP/LHC collider are all done within the Minimal Supersymmetric Standard Model. Since the photinos of the Minimal Supersymmetric Standard Model escape the detector unobserved and are recognized by missing momentum, like the neutrino of the Standard Model, a detailed study of all processes with neutrinos in the final state is made in chapter 3 for the HERA collider. These calculations also give the possibility to do further research on W- and Z-bosons. In the last chapter a study is made of the production and the signal coming from sleptons and squarks for several processes at the ep collider at LEP/LHC. Also is shown how to extract the super-symmetric signal from the Standard Model background processes. In particular the large backgrounds due to single W and Z production are considered. (author). 76 refs.; 22 figs.; 7 tabs