# HELAS and MadGraph with spin-3/2 particles

Source: [HELAS and MadGraph with spin-3/2 particles](<https://www.sota2.com/research/paper/68fa29fe1e209131ce8399e7>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2025-10-24T13:17:05.860Z

Authors: K. Hagiwara, K. Mawatari, Y. Takaesu

Published: 2010-10-20T17:26:35.000Z

## Abstract

Fortran subroutines to calculate helicity amplitudes with massive spin-3/2 particles, such as massive gravitinos, which couple to the standard model and supersymmetric particles via the supercurrent, are added to the HELAS (HELicity Amplitude Subroutines) library. They are coded in such a way that arbitrary amplitudes with external gravitinos can be generated automatically by MadGraph, after slight modifications. All the codes have been tested carefully by making use of the gauge invariance of the helicity amplitudes.

## Recorded benchmark results

A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage.

## Original sources and implementation

[Original paper](<https://arxiv.org/abs/1010.4255>)

[PDF](<https://arxiv.org/pdf/1010.4255.pdf>)