Search for the Higgs Boson in H->WW Decays at the D0 Experiment and Precise Muon Tracking

This thesis describes the search for the Higgs boson in H->WW(*)
decays in proton anti-proton collisions with data taken at the D0
experiment at the Tevatron collider. The data set was taken between
April 2002 and September 2003 and has an integrated luminosity of
approximately 147 pb^-1. An analysis of the di-muon decay channel
of the W pairs was developed which can be scaled to higher
luminosities up to the full data set to be taken until 2009 at the
Tevatron collider. The number of events observed in the current
data set is consistent with expectations from standard model
backgrounds. Since no excess is observed, cross-section limits at
95% confidence level for H->WW(*) production have been
calculated both standalone and also in combination with other
lepton decay channels. The production of W pairs is one major
background in the search of H->WW(*) decays. Hence a first
measurement of the WW production cross-section with the D0
experiment is presented. Experience gained during this analysis has
shown the precise track reconstruction is an essential tool for
both measurements. This thesis closes with a contribution to
precise tracking in the ATLAS experiment at the future Large Hadron
Collider (LHC). An alignment system for ATLAS muon drift chambers
at the cosmic ray measurement facility at LMU Munich is presented.