Dark Photons and Gravitino Like Particles: Complete EFT Operator Basis

TL;DR

This paper introduces an efficient on-shell and Young tableaux-based method for constructing complete EFT operator bases for particles of any mass and spin, including dark photons and gravitino-like particles, with an accompanying Mathematica tool.

Contribution

It develops a novel, straightforward approach to build EFT bases without auxiliary fields, applicable to particles of any spin, demonstrated with explicit bases up to dimension 8.

Findings

Constructed EFT bases for dark photons up to dimension 8.

First explicit EFT bases for spin-3/2 gravitino-like particles.

Developed a Mathematica code for automatic basis construction.

Abstract

We present a more efficient method for constructing the complete EFT operator basis for particles of any mass and spin, based on on-shell method and Young tableaux. By classifying the amplitude bases according to the polarization configurations of massive particles and using their high-energy limit, our approach can construct EFT basis in a straightforward way, without need of auxiliary fields and tedious basis decomposition. Based on this improved method, we develop a Mathematica code that can automatically construct the EFT basis for particles of any spin. As applications, the EFT bases up to d=8 are explicitly constructed for dark photons and, for the first time, for spin-3/2 gravitino like particles.