Flavor hierarchies with nonminimal irreducible representations

Abstract

We propose a new class of flavour models in which the spurion which breaks Standard Model flavour symmetries transforms in a non-minimal representation. Hierarchies in fermion masses, which arise from multiple insertions of this spurion, may be generated in a technically natural, accidental manner, from a handful of untuned $\mathcal{O}(1)$ elements in the UV. This relies explicitly on the non-Abelian nature of the symmetry, distinguishing it from standard Froggatt-Nielsen-like scenarios. The pattern of flavour violating operators at dimension-6 can radically differ from previously considered scenarios, and emphasises the need for a broad flavour programme across all generations.

5 pages + 4 pages appendices and references; v2: Matches journal version

References in corpus (5)

• General Minimal Flavor Violation
• With or without U(2)? Probing non-standard flavor and helicity structures in semileptonic B decays
• Large Top Mass and Non-Linear Representation of Flavour Symmetry
• Beyond MFV in family symmetry theories of fermion masses
• A common origin of the Higgs boson and the flavor hierarchies