A Flavor Sector for the Composite Higgs

TL;DR

This paper explores how hierarchical mixing in composite Higgs models can suppress flavor violation, allowing for new physics within LHC reach while satisfying experimental constraints.

Contribution

It introduces a scale separation approach to suppress flavor violation in composite Higgs models, compatible with current data and accessible at the LHC.

Findings

Suppression of dipole and penguin operators via scale separation.

Compatibility of 4-fermion operators with experimental data.

Potential realization in 5D models with flavor branes.

Abstract

We discuss flavor violation in large N Composite Higgs models. We focus on scenarios in which the masses of the standard model fermions are controlled by hierarchical mixing parameters, as in models of Partial Compositeness. We argue that a separation of scales between flavor and Higgs dynamics can be employed to parametrically suppress dipole and penguin operators, and thus effectively remove the experimental constraints arising from the lepton sector and the neutron EDM. The dominant source of flavor violation beyond the standard model is therefore controlled by 4-fermion operators, whose Wilson coefficients can be made compatible with data provided the Higgs dynamics approaches a "walking" regime in the IR. Models consistent with all flavor and electroweak data can be obtained with a new physics scale within the reach of the LHC. Explicit scenarios may be realized in a 5D framework, the new key ingredient being the introduction of flavor branes where the wave functions of the bulk fermions end.