English

HELAS and MadGraph with goldstinos

High Energy Physics - Phenomenology 2011-06-29 v2

Abstract

Fortran subroutines to calculate helicity amplitudes with goldstinos, which appear as the longitudinal modes of massive gravitinos in high energy processes, are added to the HELAS (HELicity Amplitude Subroutines) library. They are coded in such a way that arbitrary amplitudes with external goldstinos can be generated automatically by MadGraph, after slight modifications. All the codes have been tested carefully by making use of the goldstino equivalence theorem and the gauge invariance of the helicity amplitudes. Hadronic total cross sections for associated gravitino productions with a gluino and a squark are also presented.

Cite

@article{arxiv.1101.1289,
  title  = {HELAS and MadGraph with goldstinos},
  author = {K. Mawatari and Y. Takaesu},
  journal= {arXiv preprint arXiv:1101.1289},
  year   = {2011}
}

Comments

9 pages, 6 figures; a footnote and a reference added, version to appear in EPJC

R2 v1 2026-06-21T17:08:33.337Z