Full-hierarchy Quiver Theories of Electroweak Symmetry Breaking and Fermion Masses

TL;DR

This paper explores four-dimensional quiver theories with a large UV cutoff that can mimic extra-dimensional models, demonstrating their ability to generate fermion mass hierarchies and satisfy experimental constraints.

Contribution

It introduces full-hierarchy quiver theories derived from deconstructed extra dimensions, capable of explaining fermion masses and flavor violation without extending gauge sectors.

Findings

Fermion mass hierarchy can be generated with flavor violation within experimental bounds.

Color-octet gauge excitation mass above 3 TeV satisfies flavor constraints.

Electroweak precision tests are met without additional custodial symmetry.

Abstract

We consider quiver theories in four dimensions with a large ultra-violet cutoff. These theories require that an ordered set of vacuum expectation values for the link fields develops dynamically and can be obtained from the coarse deconstruction of extra-dimensional theories in an AdS background. These full-hierarchy quiver theories form a large class which include AdS$_5$ models as a limit, but which have a distinctive phenomenology. As an example, in this paper we show that fermions can be introduced in a way that can at the same time generate the fermion mass hierarchy and have flavor violation consistent with experimental bounds, when the mass scale of the color-octect gauge excitation is above $3 {\rm TeV}$. We also show that electroweak precision constraints are satisfied by this mass scale, without the need to extend the gauge sector to protect against custodial violation.