Composite Froggatt-Nielsen model of flavor

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 analyze the interplay of partial compositeness and the horizontal U(1) symmetry in achieving the quark masses and mixing angles. We study the contributions to ΔF=2 4-fermion operators, as well as to ΔF=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 K0-K̄0 mixing by one power of the Cabibbo angle, λC, and the dipole moments by λC2 compared with anarchic partial compositeness, possibly making the resonances accessible at LHC. 4-fermion operators of Bs-meson mixing and left-handed operators are not suppressed.