Observable jets in deep inelastic scattering as a probe of small x dynamics

Abstract

The observation of the underlying small x dynamics arising from the resummation of large terms in In 1/x QCD descriptions of the gluon distribution have been searched for ill deep inelastic scattering experiments at the electron proton collider HERA since the early 1990's. It has been recognized that the first fully inclusive measurements of the proton structure function F2 are too inclusive to identify underlying dynamics. Less inclusive quantities need to be considered. In this thesis a modified form of the BFKL equation is derived which enables the structure of the gluon emissions to be studied in small x deep inelastic scattering. The equation incorporates the resummation of the virtual and unresolved real gluon emissions and is solved to calculate the number of small x deep-inelastic events containing 0,1,2...resolved gluon jets, that is jets with transverse momenta qr > µ. We study the jet decomposition for different choices of the jet resolution parameter to look for possible signatures of BFKL dynamics in the x dependence of the exclusive observable quantities of the n-jet contributions to F(_2).We also study the application of the BFKL equation to forward jet events at HERA. We calculate the rate of deep inelastic scattering events containing two forward jets adjacent to the proton remnants and compare with the production rate of only one forward jet - the so-called Mueller process. We obtain a stable prediction for this two to one jet ratio, which may serve as a measure of the BFKL vertex function.