A composite Froggatt-Nielsen model of flavor

TL;DR

This paper introduces a composite Higgs model incorporating a Froggatt-Nielsen mechanism to address flavor issues, achieving suppressed flavor-changing effects and potentially observable resonances at the LHC.

Contribution

It presents a novel composite model combining partial compositeness with a horizontal U(1) symmetry to better control flavor violation.

Findings

Suppression of certain flavor-changing operators by factors of the Cabibbo angle.

Potential for LHC detection of resonances due to reduced flavor constraints.

Identification of parameter space where flavor violations are minimized.

Abstract

A natural composite Higgs demands the presence of light resonances at the TeV scale, that in general are in conflict with bounds from flavor and CP violation. We propose a composite model with a Froggatt-Nielsen mechanism, that offers new possibilities for the origin of flavor. We analyse the interplay of partial compositeness and the horizontal U(1) symmetry in achieving the quark masses and mixing angles. We study the contributions to $\Delta F=2$ 4-fermion operators, as well as to $\Delta F=1$ and neutron dipole operators. We find scenarios in which the contribution to Left-Right and Right-handed operators involving the first and second generations can be suppressed, in particular for a region of parameter space it is possible to simultaneously suppress the mixed-chirality contribution to $K^0-\bar K^0$ mixing by one power of the Cabibbo angle, $\lambda_C$, and the dipole moments by $\lambda_C^2$ compared with anarchic partial compositeness, possibly making the resonances accessible at LHC. 4-fermion operators of $B_s$-meson mixing and Left-handed operators are not suppressed.