HELAS and MadGraph with spin-3/2 particles

Autor: Hagiwara, K., Mawatari, K., Takaesu, Y.
Rok vydání: 2010
Předmět:
Zdroj: Eur.Phys.J.C71:1529,2011
Druh dokumentu: Working Paper
DOI: 10.1140/epjc/s10052-010-1529-6
Popis: 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.
Comment: 12 pages, 4 figures; sections rearranged, typos corrected, version to appear in EPJC
Databáze: arXiv