Experimental Particle Physics
Schumacher group
Unravelling the origin of electroweak symmetry breaking and of the masses of elementary particles is one of the most fascinating and pressing topics of contemporary particles physics. Usually the above question is explained via the Higgs-Brout-Englert-Kibble-Guralnik-Hagen mechanism, which predicts the existence of elementary spinless particles: the Higgs boson(s). This particle is the only missing ingredient of the Standard Model of particle physics and the mass of the Higgs boson the last undetermined parameter.
Supersymmetry (SUSY) is the theoretically most favoured extension of the Standard Model. It potentially solves several open questions of the Standard Model, e.g. the origin of Dark Matter observed in the universe. SUSY predicts the existence of at least five Higgs bosons (three neutral and two charged Higgs bosons altogether).
The LHC has the unique opportunity to test these predictions as it is the highest energy particle collider ever built. It will finally answer a question unsolved for 40 years: whether Higgs bosons as predicted by the SM or its SUSY extensions are realised in nature or not. Our group focuses on searches for these Higgs bosons in the Standard Model (SM) and its minimal supersymmetric extension (MSSM).In addition our group is responsible for operating a so-called local TIER2 computing center, using Grid computing technology, for data analysis at the LHC. This Grid cluster is part of the ATLAS computing model which is embedded in the Worldwide LHC Computing Grid (WLCG) and in the interdisciplinary Freiburg Black Forest Grid (BFG).
In detail, the following topics comprise our main focus of research:
- the search for neutral Higgs bosons decaying to a pair of tau leptons in the SM and MSSM
- the search for charged Higgs bosons decaying into a tau leptons and its neutrino in extensions of the SM, in particular, the MSSM
- optimisation of the identification of tau leptons
- optimisation of mass reconstruction techniques for Higgs bosons searches involving tau leptons
- development of novel methods to study, control, reject and estimate background processes for the aforementioned searches
- optimisation of the data analysis chain when using the Grid infrastructure