Rapidity gap physics at contemporary colliders

Abstract

This thesis is concerned with the theory and the phenomenology of rapidity gap processes. We perform perturbative calculations of energy flow observables in jet-gap-jet processes, which consist of resummed primary emission calculations specific to the soft gluon geometry at HERA and an estimate of non-global (secondary emission) effects in clustered energy flow observables. The resulting predictions agree well with H1 data. We also study hard diffraction and use a factorised model, with a Monte Carlo event generator, to make detailed predictions for gap-jet-gap events at the Tevatron. We find that we can describe the data in a natural way by using HERA parton densities and a gap surivial factor consistent with theoretical estimates.