HELAS and MadGraph with spin-3/2 particles
High Energy Physics - Phenomenology
2011-02-09 v2
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.
Keywords
Cite
@article{arxiv.1010.4255,
title = {HELAS and MadGraph with spin-3/2 particles},
author = {K. Hagiwara and K. Mawatari and Y. Takaesu},
journal= {arXiv preprint arXiv:1010.4255},
year = {2011}
}
Comments
12 pages, 4 figures; sections rearranged, typos corrected, version to appear in EPJC