Froggatt-Nielsen meets the SMEFT

Journal Article · 02 October 2024 · Journal of High Energy Physics (Online)

DOI: https://doi.org/10.1007/jhep10(2024)017 · OSTI ID:2476027

Loisa, Eetu  ^[1]; Talbert, Jr., James Ronald  ^[2]

---

1. Univ. of Cambridge (United Kingdom)
2. Univ. of Cambridge (United Kingdom); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

We study the matching of Froggatt-Nielsen theories of flavour onto the Standard Model Effective Field Theory (SMEFT), upon integrating out a heavy Beyond-the-Standard-Model (BSM) scalar ‘flavon’ whose vacuum expectation value breaks an Abelian flavour symmetry at energies Λ_FN well above the electroweak scale, Λ_FN > Λ_SM. We include matching contributions to the infrared d_SM = 6 (Warsaw basis) SMEFT sourced from ultraviolet contact terms suppressed up to order 1/$${\Lambda}_{\textrm{UV}}^2$$ in the Froggatt-Nielsen Lagrangian, where Λ_UV > Λ_FN is an arbitrary ultraviolet scale where further unspecified BSM particles are dynamical. This includes tree-level (one-loop) ultraviolet diagrams with d_FN = 6 (5) effective vertices. We first do so with a toy model, but then generalize our findings to arbitrary Frogatt-Nielsen charges. Our results indicate a rich and non-trivial signature of Froggatt-Nielsen theories on the (otherwise) model-independent operators of the SMEFT, and we briefly speculate on extending our analysis to broader classes of BSM flavour models, e.g. non-Abelian and/or gauged theories. We thus take an important step towards determining how to use rapidly developing theoretical and experimental SMEFT technologies to gain unambiguous insight into the SM’s longstanding fermion flavour puzzle.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 2476027
• Report Number(s): LA-UR--24-21703
• Journal Information: Journal of High Energy Physics (Online), Journal Name: Journal of High Energy Physics (Online) Journal Issue: 10 Vol. 2024; ISSN 1029-8479
• Publisher: Springer NatureCopyright Statement
• Country of Publication: United States
• Language: English