Higgs decay into diphoton in the Composite Higgs Model

Abstract

We explore the Higgs couplings to gauge bosons in the minimal $SO(5)/SO(4)$ 4D composite Higgs model. The pions scatterings put unitary constraints on the couplings and therefore determine the branch ratios of various Higgs decays. Through fine tuning the parameters, enhancement of Higgs to diphoton rate is possible to be achieved with the existence of vector meson fields.

Comments: 19 pages, and 4 figures, new form factor for H-Z-photon coupling from non diagonal gauge interaction is added in the appendix, final version