H→τ+τ− and H±→τν feasibility studies with ATLAS at the LHC

The discovery of the origin of electroweak symmetry breaking, realized in the Standard Model and in some models beyond this theory by the Higgs mechanism, is one of the main goals of the ATLAS experiment at the Large Hadron Collider. This mechanism predicts the existence of one or more scalar particles, the Higgs boson(s). Higgs boson decay modes to tau leptons, such as H→τ+τ−, are very important as they could play a crucial role in searches within the challenging 120 – 140 GeV mass region. This channel is also important in supersymmetric extensions of the Standard Model through the associated production of the Higgs bosons with heavy quarks or by gluon fusion. Finally, the observation of a charged Higgs boson would constitute irrefutable evidence for physics beyond the Standard Model. A light charged Higgs boson would be produced in top quark decays through t→bH+, and would be likely to decay to a tau lepton and a neutrino. This paper summarizes recent ATLAS studies focusing on the above channels and concentrates on several experimental aspects of these analyses.