Viability of light-Higgs strongly-coupled scenarios

Mercoledi 27 febbraio, alle ore 16 in sala riunioni (I piano) il dr. Juan Jose Sanz-Cillero (Physics Department, Madrid University, Spain) terra' un seminario dal titolo:
Viability of light-Higgs strongly-coupled scenarios

Abstract:
We present a one-loop calculation of the oblique S and T parameters within strongly-coupled models of EW symmetry breaking with a Higgs-like boson and analyze the phenomenological implications of the available electroweak precision data. Using the dispersive representation of Peskin and Takeuchi and imposing a vanishing vector form factor at high energies, we obtain S and T at the next-to-leading order in terms of a few resonance parameters. A reasonable range is experimentally allowed for the parameters of the strongly coupled model, allowing vector and axial-vector resonance masses above the TeV scale and a coupling between the new scalar and WW close to that in the Standard Model. A reduction of the lightest resonance mass implies an important decreasing of the latter. Based on composite Higgs SO(5)/SO(4) models it is possible to reach similar conclusions.