====== A2b: Vector-Boson Scattering and Multi-Boson Production======

^Principal Investigators^^
|[[http://www.physik.uni-siegen.de/tp1/research/researchgroups/kilian.html?lang=de | Prof. Wolfgang Kilian   ]] |University of Siegen  | 
|[[ https://www.itp.kit.edu/memberpages/zeppenfeld | Prof. Dieter Zeppenfeld ]] |Karlsruhe Institute of Technology|


==== Subject ====
We study processes at the LHC which involve interactions of four or more electroweak vec- tor or Higgs bosons. If there is new physics in the Higgs or electroweak sector, we expect deviations from the SM in vector-boson scattering and multi-boson production. The deviati- ons rise with energy and thus become significantly constrained by unitarity relations. We develop universal schemes for dealing with this fact, properly matched to the effective- theory description at low energy.

====Topics ====

  - Vector-boson scattering: 
    * study all charged and neutral bosons (+ photon, + Higgs); 
    * compare and combine analytical and numerical methods; 
    * match to D=6 ⊕ D=8 low energy effective operators coherently; signal vs background separation for future LHC run;
  - Predictions and limits for $q \bar q \to n$~bosons ($n > 2$): 
    * disentangle and relate final states in $q \bar q \to VVV$ and $VVVV$;
    *  visible and invisible new physics as inelastic scattering;
  - Combine predictions and apply to incoming LHC results: 
    *unitarity relations apply to all multi-boson processes coherently; 
    *complete simulations and tools for meaningful data analysis; 
    *implications for effective theory and (simplified) models;  
    *model-independent interpretation and sensitivity to Higgs potential.