HELAS and MadGraph with spin-3/2 particles

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.

12 pages, 4 figures; sections rearranged, typos corrected, version to appear in EPJC

References in corpus (8)

• Theories with Gauge-Mediated Supersymmetry Breaking
• MadGraph/MadEvent v4: The New Web Generation
• MadEvent: Automatic Event Generation with MadGraph
• Automatic Generation of Tree Level Helicity Amplitudes
• Thermal Production of Gravitinos
• Search for supersymmetry with a light gravitino at the Fermilab Tevatron and CERN LEP colliders
• Supergravity at Colliders
• Weak boson fusion production of supersymmetric particles at the LHC

Cited by in corpus (12)

• MadGraph 5 : Going Beyond
• ALOHA: Automatic Libraries Of Helicity Amplitudes for Feynman diagram computations
• Beyond the Minimal Supersymmetric Standard Model: from theory to phenomenology
• The New Look pMSSM with Neutralino and Gravitino LSPs
• Lessons and Prospects from the pMSSM after LHC Run I: Neutralino LSP
• Simulating spin-3/2 particles at colliders
• Gravitino LSP and leptogenesis after the first LHC results
• Comprehensive Constraints on a Spin-3/2 Singlet Particle as a Dark Matter Candidate
• HELAS and MadGraph with goldstinos
• Light gravitino production in association with gluinos at the LHC
• Associated production of light gravitinos in e^+e^- and e^-γcollisions
• Monophoton signals in light gravitino production at $e^{+}{e}^{-}$ colliders