# The Rise of SMEFT On-shell Amplitudes

## TL;DR

This paper establishes a connection between SMEFT in the Warsaw basis and massive on-shell amplitudes, focusing on the electroweak sector, enabling new methods for analyzing scattering processes.

## Contribution

It introduces an on-shell basis for SMEFT that facilitates the study of scattering amplitudes using recursion relations, advancing the on-shell formulation of massive EFTs.

## Key findings

- Mapped SMEFT to on-shell amplitudes in the electroweak sector
- Fixed an on-shell basis compatible with recursion relations
- Compared Feynman rules with broken phase amplitudes

## Abstract

We present a map between the tree-level Standard Model Effective Theory (SMEFT) in the Warsaw basis and massive on-shell amplitudes. As a first step, we focus on the electroweak sector without fermions. We describe the Feynman rules for a particular choice of input scheme and compare them with the 3-point massive amplitudes in the broken phase. Thereby we fix an on-shell basis which allows us to study scattering amplitudes with recursion relations. We hope to open up new avenues of exploration to a complete formulation of massive EFTs in the on-shell language.