Electron specific track fitters and Jpsi resonance studies in ATLAS

This thesis discusses the reconstruction of J/psi to electron pairs based on fully simulated ATLAS Monte Carlo samples. A possible trigger strategy is described, taking advantage of the possible presence of a muon in the final state in bb production once one b-hadron decays into J/psi+X, followed by J/psi decay into e+e-. The tracks belonging to low-energy electrons are reconstructed using a dedicated algorithm, taking into account bremsstrahlung effects. The performance of this algorithm is compared with the other ATLAS track fitters and the potential of using this tracking algorithm to map the Inner Detector material is presented. The improvement in separation of indirect from prompt J/psi, by separately considering two kinematical configurations, `cowboys' and `sailors', is also presented, along with a feasibility study of measuring the ratio of indirect to prompt J/psi.