Particle and Astro-Particle Physics Seminars

# Strongly interacting WW, ZZ and HH at high energies

 Description In this talk we review the main ATLAS and CMS results leading to the recent finding of a 125-GeV light Higgs-like boson. In the context of the Minimal Standard Model (MSM) this implies a W_L W_L system weakly interacting. However this is an exceptional feature not generally true if new physics exists beyond the mass gap found at the LHC up to 700 GeV. By using an extension of the Electroweak Chiral Lagrangian, including one light scalar (LHCh), it is possible to study the W_L W_L , Z_L Z_L and HH scattering at high energies relevant for the future LHC data. In this talk we show the results of our computations at the one-loop level by using the Equivalence Theorem. Then we introduce the Inverse Amplitude (IAM) method in this context to unitarize the partial waves. For most of the parameter space, the scattering is strongly interacting (with the MSM being a remarkable exception) and the IAM method produces poles in the second Riemann sheet of the amplitude in many cases that have a natural interpretation as dynamical resonances. Therefore, the finding of the Higgs boson could be more a signal for new strongly interacting physics (composite Higgs) rather than a confirmation of the SM. Slides