Composite or elementary? Probing the nature of the Higgs

Abstract

I discuss consequences of electroweak symmetry breaking by strong dynamics, assuming the existence of a light composite scalar appearing as a pseudo-Goldstone boson of some global symmetry of the new strongly interacting sector. In such a scenario, the composite scalar has properties very similar to the Standard Model Higgs, but the existence of additional resonances with different spins is also expected. Properties and phenomenology of lightest spin-1 resonances are considered in a simple general effective Lagrangian description. The question whether the effects of spin-1 resonances can be observed at the LHC, shedding light on the nature of the Higgs boson, is addressed.