Unitarity in composite Higgs approaches with vector resonances

Abstract

We examine a simple Composite Higgs Model (CHM) with vector resonances in addition to the Standard Model (SM) fields in perturbation theory by using the $K$-matrix method to implement unitarity constraints. We find that the $W_L{W}_L$ scattering amplitude has an additional scalar pole (analogous to the $\sigma$ meson of QCD) as in generic strongly interacting extensions of the SM. The mass and width of this dynamically generated scalar resonance are large and the mass behaves contrary to the vector one, so that when the vector resonance is lighter, the scalar one is heavier, and vice versa. We also attempt an interpretation of this new resonance. Altogether, the presence of the vector state with the symmetries of the CHM improve the low-energy unitarity behavior also in the scalar-isoscalar channel.

16 pages, 14 figures

References in corpus (10)

• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• Search for high-mass dilepton resonances in pp collisions at sqrt(s) = 8 TeV with the ATLAS detector
• LHC Signals for Warped Electroweak Neutral Gauge Bosons
• Search for physics beyond the standard model in dilepton mass spectra in proton-proton collisions at sqrt(s) = 8 TeV
• Search for massive resonances decaying into pairs of boosted bosons in semi-leptonic final states at sqrt(s) = 8 TeV
• The pion-pion scattering amplitude. III: Improving the analysis with forward dispersion relations and Roy equations
• LHC Signals for Warped Electroweak Charged Gauge Bosons
• Search for new resonances decaying via WZ to leptons in proton-proton collisions at sqrt(s) = 8 TeV
• Non Minimal Terms in Composite Higgs Models and in QCD

Cited by in corpus (2)

• Off-shell effects in Higgs processes at a linear collider and implications for the LHC
• The Dynamical Composite Higgs