Mehrfache partonische Wechselwirkungen bei hadronischen Streuungen

The common approach for simulation of hadronic scattering events is to combine a perturbative description of the hardest partonic interaction with measurable structure functions which reflect non-perturbative properties of hadrons. At present this approach requires exactly one parton of each hadron to enter this interaction.

Analyses of proton-antiproton scattering at Tevatron and first analyses of proton-proton scattering at LHC show deviations from this simulations, which seam to indicate multiple partons of a single hadron entering a scattering event. Yet for simulation of such events there are no appropriate multiple parton structure functions available.

We introduce two different approaches for factorization of multiple parton scattering which approximate multiple structure functions by single structure functions. Furthermore we introduce a procedure which allows a simultaneous evolution of the factorization scale of both multiple parton interactions and initial state radiation.

Finally we elaborate an efficient implementation of a Monte Carlo generator for this simultaneous evolution, considering limitations of finite memory and CPU power. In this framework we treat multiple parton interactions as QCD correction to the hardest interaction.