This article describes the potential of the ATLAS experiment at the LHC to discover Higgs bosons in Beyond the Standard Model (BSM) scenarios. Two examples are discussed. First the discovery ...potential for Higgs bosons in the Minimal Supersymmetric Standard Model (MSSM) is evaluated. At least one Higgs boson can be observed for the whole accessible parameter space. Second the case of invisibly decaying Higgs bosons is discussed. A Higgs boson with a large branching ratio into invisible particles can also be discovered.
Motivated by the high muon momentum resolution and identification efficiency achievable with the ATLAS detector, currently being installed at CERN, we explore the observability of the supersymmetric ...h/A/H decays to two muons. The high experimental resolution in this decay mode compensates to some extent for the suppression of the branching ratio, with respect to the h/A/H → τ τ decays. The search is performed in a wide Higgs mass range, starting from 110 GeV/c2. In the case of gg → bb(h/H/A) production mode, the additional b-jets produced in association with the h/H/A bosons are used to suppress the background. Using fully simulated signal and background event samples, we study the performance of the reconstruction algorithms relevant to the analysis, such as the muon reconstruction, b-tagging and the measurement of the missing energy. The influence of the detector misalignment on the reconstruction performance is also taken into consideration. Emphasis is given on the optimization of the event selection procedure and the corresponding selection criteria, taking into account the different background composition depending on the mass range in which the Higgs search is performed.
This Report summarizes the results of the first 10 months' activities of the LHC Higgs Cross Sections Working Group. The main goal of the working group was to present the status-of-art on Higgs ...Physics at the LHC integrating all new results that have appeared in the last few years. The Report is more than a mere collection of the proceedings of the general meetings. The subgroups have been working in different directions. An attempt has been made to present the first Report from these subgroups in a complete and homogeneous form. The subgroups' contributions correspondingly comprise the main parts of the Report. A significant amount of work has been performed in providing higher-order corrections to the Higgs-boson cross sections and pinning down the theoretical uncertainty of the Standard Model predictions. This Report comprises explicit numerical results on total cross sections, leaving the issues of event selection cuts and differential distributions to future publications. The subjects for further study are identified.
This report summarizes the activities of the SM and NLO Multileg Working Group of the Workshop "Physics at TeV Colliders", Les Houches, France 8-26 June, 2009.
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