Final Activity Report Summary - ATLAS-CPPM-SUSY (Searching for supersymmetry at LHC: Study Program with ATLAS at CPPM Marseille) The amount of money provided by the European Commission to Dr Laurent Vacavant has indeed been used to hire a junior experienced researcher, Dr Lorenzo Feligioni, to help Dr Vacavant to perform his research work. Lorenzo Feligioni has been recruited in January 2006 as a junior experienced researcher, to work with the ATLAS group at the Centre de Physique des Particules de Marseille (CPPM).The experiment named 'A toroidal LHC apparatus' (ATLAS) is a particle physics experiment created with the aim of exploring the fundamental nature of matter and the basic interactions between the smallest known constituents of our universe. A new frontier for particles physics is expected to unveil in the proton-proton collisions when the Large Hadron Collider (LHC), located at the European Laboratory for Particle Physics (CERN) in Geneva, will start to be operative. With the unprecedented energy of 14 TeV these collisions could bring light to the mechanism of electro-weak symmetry breaking, either by proving or excluding the standard model version, the Higgs mechanism, or in one of its most natural extensions, supersymmetry.The ATLAS group at CPPM is in charge of the end-cap electromagnetic calorimeter, and together with other institutions in the design, construction and commissioning of the pixel vertex detector. It is also involved in the development of the high level trigger. The group is preparing data analysis by studying b quark identification algorithms and methods of top quark reconstruction. Top quarks are expected to be produced copiously at the LHC and other than studying their important properties they could be used for the calibration of the ATLAS detector. In case of the existence of a light SM or supersymmetric Higgs boson one of the signature would be to be produced together with top quarks before decaying in a b anti-b quark pair.During these two years of activity Lorenzo Feligioni work has been mainly the preparation of an up to date sensitivity study for the detection of a light SM Higgs boson produced together with top anti-top quark pair, ttH(H->bb), after the first three years of ATLAS data taking. This study is part of an ongoing effort of the ATLAS collaboration to re-evaluate the physics capability of the experiment using the latest detector simulation and algorithm performances. Lorenzo Feligioni is co-editor of the ttH(H->bb) sensitivity study done in the framework of ATLAS computing system commissioning (CSC) effort.
