A2b: Vector-Boson Scattering and Multi-Boson Production

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.

1. 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;
2. 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;
3. 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.