Towards a composite Higgs and a partially composite top quark

Abstract

We have calculated quantities of interest to a theory of compositeness. The lattice model, approximating the candidate theory, is the SU(4) gauge theory coupled to fermions in two color representations. For the composite Higgs, a current correlator gives one of the ingredients of the effective Higgs potential. For the partially composite top quark, we have hyperbaryon matrix elements that govern mixing of the fundamental quark with its heavy composite partner. The matrix elements turn out to be so small that the theory is disfavored as a source of a realistic top mass.

Loop-generated neutrino masses in composite Higgs models

“…However, the current results cannot be used to exclude the model as a candidate for a CH model with PC, because the spectrum for the top partners is not available yet, as the fermions in the anti-symmetric representation are not fully dynamical in the most recent simulations [63]. A study of models based on SU(4) TC is at a more advanced status [64][65][66][67], however targeting a different class of cosets. Results with fully dynamical fermions show that the spin-1/2 resonances, candidates to be top partners, have masses much larger than f [65].…”

Composite electroweak sectors on the lattice

“…The study of the matrix element relevant in determining the strong sector contribution to the mass of the top quark has been presented in [62] and summarises the recent results obtained in [63]. At the scale L SCT , the linear mixing between the chimera baryon and the massless top quark is controlled by two coupling constant G L,R generated by the extended sector that can be thought as "Fermi" constants.…”

“…The authors argue that imposing y t ∼ 1, implies that Λ UV cannot be much larger than F 6 as the "model" would require it. We refer to [62] and to [63] for more details.…”