Design and implementation of the object-oriented fast simulation program for the ATLAS experiment and its use to determine the discovery potential of the Higgs Boson via the channel h- > ZZ- > bbl+l-

The design and implementation of the object-oriented fast simulation program Atlfast is described for the ATLAS experiment at the CERN particle physics laboratory in Switzerland. Fast simulations use parametrised energy and momentum smearing in order to recreate the detection efficiency and particle identification of a real experimental detector, without the time-consuming computation required for full detector simulation. Additionally, an object-oriented program for performing user-defined physics analyses is described. This program is released for general use by the ATLAS collaboration and is designed for use with, but not restricted to, physics output from the Atlfast fast simulation program. These programs are demonstrated in a physics study of the feasibility of discovering the Higgs boson at the ATLAS experiment, using the discovery channel ho > Z Z * > bb l+l via weak vector boson fusion in the mass range 150 GeV - 200 GeV. It is found that this channel does not significantly increase the discovery potential over this mass range, achieving the observa tion threshold of 3a only after 3 years high luminosity running at the upper end of the mass range.