Hamburg 2016 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

T: Fachverband Teilchenphysik

T 46: Higgs-Boson (Zerfall in Tau-Leptonen) III

T 46.2: Talk

Tuesday, March 1, 2016, 17:00–17:15, VMP5 HS A

Study of τ-spin correlations in Z/γ→τ⁺τ⁻ decays at ATLAS — •Maike Hansen, Philip Bechtle, Klaus Desch, Christian Grefe, and Peter Wagner — Universität Bonn

Major Beyond Standard Model theories, such as supersymmetry, predict a CP-mixing in the Higgs to fermions sector. Such a mixing is not excluded by any of the previous measurements.

In the H→ττ decay channel, the CP-mixing can be measured based on angles between the τ-decay planes. In the hadronic τ-decay modes, this measurement relies on a high purity τ-decay mode classification and a good reconstruction of the (hadronic) τ-decay products. All this is available now due to the new τ reconstruction in ATLAS.

For this analysis, we focus on fully hadronic Z/γ → τ⁺τ⁻ decays, the major, irreducible background for a Higgs CP-measurement. After splitting up the phase space kinematically, all methods can be applied in the same way as for the Higgs. This way, from a measurement in Z/γ → τ⁺τ⁻ decays, systematic effects as well as the sensitivity on a Higgs CP-measurement can be understood.