J. J. Sakurai Prize for Theoretical Particle Physics Lecture: Some QCD aspects of physics beyond the standard model

The nature of observable events at the LHC is mainly determined by QCD physics, i.e. strong interactions. The search for new physics obviously implies a desire to go beyond QCD. Nevertheless, also in cases where non-QCD processes are studied, new aspects of QCD physics may enter the back door. We here give three examples: decays with R-parity violation in SUSY, the formation of long-lived R-hadrons in SUSY, and parton showers and hadronization in Hidden Valley scenarios. These three possibilities have been implemented in the general-purpose PYTHIA event generator, so that detailed studies of consequences can be performed.