Complete Lagrangian and Set of Feynman Rules for Scalar Leptoquarks

TL;DR

This paper provides a comprehensive Lagrangian and Feynman rules for scalar leptoquarks, facilitating automated analyses of their interactions relevant to flavor anomalies and muon magnetic moment discrepancies.

Contribution

It introduces the complete Lagrangian and Feynman rules for five scalar leptoquark representations, including self-interactions and couplings to SM particles, with publicly available model files.

Findings

Complete set of Feynman rules for scalar leptoquarks

Includes self-interactions and couplings to SM particles

Model files available online for automation

Abstract

Leptoquarks (LQs) have attracted increasing attention within recent years, mainly since they can explain the flavor anomalies found in $R(D^{(*)})$, $b \rightarrow s \ell^+ \ell^-$ transitions and the anomalous magnetic moment of the muon. In this article, we lay the groundwork for further automated analyses by presenting the complete Lagrangian and the corresponding set of Feynman rules for scalar leptoquarks. This means we consider the five representations $\Phi_1, \Phi_{\tilde1}, \Phi_2, \Phi_{\tilde2}$ and $\Phi_3$ and include the triple and quartic self-interactions, as well as couplings to the Standard Model (SM) fermions, gauge bosons and the Higgs. The calculations are performed using FeynRules and all model files are publicly available online at https://gitlab.com/lucschnell/SLQrules.