Composite Higgs models consist of four-dimensional asymptotically-free gauge field theories. Each model may lead to a confinement-deconfinement transition and a phase transition associated with the spontaneous breaking of a global symmetry that realizes the standard model Higgs field as a pseudo-Nambu-Goldstone boson. In this talk, I will discuss order of thermal phase transitions in various composite Higgs models based on the argument of universality. In particular, we focus on phase transitions associated with the global symmetry breaking by studying the renormalization group flow using the ϵ-expansion at the one-loop order.
We find that first-order phase transitions are favored in some of composite Higgs models. If I have a time, I would like to discuss the confinement-deconfinement transition in a UV-completed composite Higgs model based on a Sp(2Nc) gauge theory.