Top quark induced effective potential in a composite Higgs model

TL;DR

This paper investigates a composite Higgs model where a new strong sector produces the Higgs as a pseudo Nambu-Goldstone boson, analyzing the top quark's role and the conditions for electroweak symmetry breaking.

Contribution

It derives the top quark Yukawa coupling and effective potential in a non-perturbative composite Higgs framework using baryonic correlation functions and large-N analysis.

Findings

Top quark contribution can induce electroweak symmetry breaking.

Large-N limit suggests light baryons coupled to the top quark.

Model is amenable to lattice QCD studies.

Abstract

We consider non-perturbative aspects of a composite Higgs model that serves as a prototype for physics beyond the Standard Model, in which a new strongly interacting sector undergoes chiral symmetry breaking, and generates the Higgs particle as a pseudo Nambu-Goldstone boson. In addition, the top quark couples linearly to baryons of the new strong sector, thereby becoming partially composite. We study the dynamics leading to the top quark Yukawa coupling as well as the top quark contribution to the effective potential for the Higgs, obtaining expressions for these couplings in terms of baryonic correlation functions in the underlying strongly interacting theory. We then show that a large-N limit exists in which the top quark contribution to the Higgs effective potential overcomes that of the weak gauge bosons, inducing electroweak symmetry breaking. The same large-N limit also suggests that the baryons that couple to the top quark may be relatively light. This composite Higgs model, and similar ones, can be studied on the lattice with the methods developed for lattice QCD.