Non Minimal Terms in Composite Higgs Models and in QCD

Abstract

We introduce a general parametrisation for theories where the Higgs is a Goldstone boson that encompasses all existing models. Our construction deviates from extra-dimensional or deconstructed theories through the inclusion of "non-local" interactions in theory space. These terms are necessary to reproduce the most general 4D effective lagrangian compatible with the symmetries. After showing the relation of our formalism to the Callan-Coleman-Wess-Zumino effective lagrangian we apply our framework to SO(5)/SO(4) composite Higgs models studying the implications for the Higgs potential, coupling of resonances and S-parameter. We also outline the relevance of non-minimal terms in effective descriptions of QCD, studying the electro-magnetic splitting of pions and the correlation between L_9 and L_10 in the chiral lagrangian.

Comments: 29 pages, v2 minor changes