Anarchy with linear and bilinear interactions

TL;DR

This paper proposes a novel flavor model where bilinear interactions dominate certain fermion masses, allowing new physics to be below 10 TeV while satisfying flavor and CP violation constraints.

Contribution

It introduces a hybrid flavor mechanism combining bilinear and partial compositeness interactions, reducing the scale of new physics needed for flavor safety.

Findings

Neutron and electron dipole moments are compatible with new physics below 10 TeV.

Most stringent bounds come from $ ext{Δ}F=2$ and $ ext{Δ}F=1$ operators involving left-handed quarks.

New state masses are constrained to be above approximately 6-7 TeV.

Abstract

Composite Higgs models with anarchic partial compositeness require a scale of new physics ${\cal O}(10-100)$ TeV, with the bounds being dominated by the dipole moments and $\epsilon_K$. The presence of anarchic bilinear interactions can change this picture. We show a solution to the SM flavor puzzle where the electron and the Right-handed quarks of the first generation have negligible linear interactions, and the bilinear interactions account for most of their masses, whereas the other chiral fermions follow a similar pattern to anarchic partial compositeness. We compute the bounds from flavor and CP violation and show that neutron and electron dipole moments, as well as $\epsilon_K$ and $\mu\to e\gamma$, are compatible with a new physics scale below the TeV. $\Delta F=2$ operators involving Left-handed quarks and $\Delta F=1$ operators with $d_L$ give the most stringent bounds in this scenario. Their Wilson coefficients have the same origin as in anarchic partial compositeness, requiring the masses of the new states to be larger than ${\cal O}(6-7)$ TeV.