Project Brief Jean-Sebastien Bouillard Supervisor: Jon Butterworth This project is a continuation of the project carried out by Sunil Patel in 2000/2001 and focuses on development and use of the fast simulation programme for the ATLAS particle physics detector at the Large Hadron Collider (LHC) at CERN. ATLAS will detect proton-proton collisions at a higher energy than ever before observed. Understanding the detector response and the multitude of particle produced is a major challenge. The ATLAS fast simulation (ATLFast) is a C++ Monte Carlo program developed at UCL for the whole of ATLAS. The project is to test & develop this programme by simulating WW production events (a promising search channel for the Higgs boson) and to suggest ways in which these events could be most efficiently and accurately measured.