Composite Higgs sketch

The couplings of a composite Higgs to the standard model elds can deviate substantially from the standard model values. In this case perturbative unitarity might break down before the scale of compositeness, Λ, is reached, which would suggest that additional composites should lie well below Λ. In this paper we account for the presence of an additional spin 1 custodial triplet ρ ^±,0. We examine the implications of requiring perturbative unitarity up to the scale Λ and find that one has to be close to saturating certain unitarity sum rules involving the Higgs and ρ couplings. Given these restrictions on the parameter space we investigate the main phenomenological consequences of the ρ's. We nd that they can substantially enhance the h→ γγ rate at the LHC even with a reduced Higgs coupling to gauge bosons. The main existing LHC bounds arise from di-boson searches, especially in the experimentally clean channel ρ^± →W^±Z → 3l + ν. We find that a large range of interesting parameter space with 700 GeV mρ2TeV is currently experimentally viable.