# Massive On-Shell Supersymmetric Scattering Amplitudes

## TL;DR

This paper develops a covariant on-shell superspace formalism for massive particles in four dimensions, enabling systematic construction of supersymmetric scattering amplitudes with high-spin particles using the massive spinor helicity method.

## Contribution

It introduces a new on-shell superspace framework for massive particles, facilitating the derivation of all possible three-particle supersymmetric amplitudes for spins up to one.

## Key findings

- Constructed massive on-shell superfields.
- Derived all possible $
abla=1$ three-particle amplitudes.
- Demonstrated conceptual and computational simplicity.

## Abstract

We introduce a manifestly little group covariant on-shell superspace for massive particles in four dimensions using the massive spinor helicity formalism. This enables us to construct massive on-shell superfields and fully utilize on-shell symmetry considerations to derive all possible $\mathcal{N}=1$ three-particle amplitudes for particles of spin as high as one, as well as some simple amplitudes for particles of any spin. Throughout, the conceptual and computational simplicity of this approach is exhibited.