# Subproject B5: Precision Calculations for Higgs and BSM Physics at the LHC

Project leaders:

Prof. Dr. Dieter Zeppenfeld, Institute of Theoretical Physics, Karlsruhe Institute of Technology
(KIT)

Prof. Dr. Margarete Mühlleitner, Institute of Theoretical Physics, Karlsruhe Institute of Technology (KIT)

Summary:

Exploring new phenomena at the Terascale is the major challenge for particle physics in the next two decades and beyond. Experiments at the Large Hadron Collider (LHC) will reveal the mechanism of electroweak symmetry breaking and may discover new physics beyond the Standard Model. The analysis of Higgs and beyond the Standard Model phenomena at colliders requires complex higher-order calculations for signal and background processes and phenomenological studies to test and explore new physics models. A prominent example is the determination of Higgs couplings. LHC Higgs boson production and decay data can be used to extract gauge and fermion couplings of Higgs bosons with an accuracy of 10%, provided cross sections and branching ratios can be predicted with similar precision. Further examples of LHC physics analyses, which rely crucially on precise theoretical calculations, include the determination of electroweak gauge boson couplings or the extraction of supersymmetric parameters from cascade decays.

The overall goal of project B5 is to derive accurate predictions for Higgs and BSM signal and background processes at the LHC, and to employ these predictions for phenomenological analyses. The project builds on substantial previous work by the principal investigators on NLO corrections for multi-parton processes at the LHC, vector boson and Higgs production and decay in the Standard Model and beyond, precision calculations in supersymmetric models and the exploration of alternative physics scenarios. Vector boson production, for example, constitutes an important signal and background reaction at hadron colliders, and the comprehensive current work on NLO QCD corrections to such processes will be continued in the third funding period. A strong emphasis will also be placed on precision calculations for supersymmetric Higgs bosons, both in the minimal supersymmetric model and non-minimal extensions, and on higher-order corrections to the production and decay of supersymmetric particles in general. A new aspect of the proposal in the third funding period will be the analysis of alternative new physics models, like models with extra space dimensions or composite Higgs bosons.

The third funding period of the SFB coincides largely with the first four years of high energy data provided by the LHC. More emphasis will thus be placed on phenomenological investigations, in particular the determination of Higgs and vector boson couplings in the Standard Model and beyond, the thorough analysis of supersymmetric particle production and decay, and the exploration of alternative physics models. The precision calculations which we have carried out in the past, or which we propose for the upcoming funding period, and the experience in phenomenological collider physics analyses will allow us to make major contributions to the first exploration of the Terascale, the elucidation of the mechanism of electroweak symmetry breaking and the search for physics beyond the Standard Model.

Last Change: 20th June 2011