How to probe electroweak physics and beyond with tau lepton at hadron colliders

par Dr Romain Madar (Freiburg)

vendredi 24 janv. 2014, 14:30 → 15:30 Europe/Paris

Salle 9109 (Dpt. Physique)

The tau lepton sector of the Standard Model provides valuable information to better understand the physics at the electroweak scale and beyond. In the current experimental landscape, the most important step is to identify (or not) the new boson as the Standard Model Higgs boson. The tau pair decay mode of the Higgs boson provides, together with the H->bb process, unique access to the coupling strength between the Higgs field and two elementary fermions, and therefore provides the opportunity to test the proportionality between mass and coupling in the fermionic sector. Alternatively if the discovered boson doesn't behave as predicted, its nature will need to be understood in a wider theoretical context. Several Standard Model extensions, such as supersymmetry, predict new particles that can decay into tau leptons. On the other hand, the tau lepton is the only lepton which can decay into hadrons(s) and this makes the physics involving these leptons very challenging to probe at hadron colliders. The different techniques developed at hadron collider experiments (mainly D0 and ATLAS) to reconstruct and identify the hadronic decay of tau leptons will be presented together with their recent improvements. Then the physics probed by tau final states will be described, particularly emphasizing the Higgs physics and the associated perspectives.