HELAC-PHEGAS: automatic computation of helicity amplitudes and cross sections

Abstract

HELAC-PHEGAS is a FORTRAN based package that is able to compute automatically and efficiently tree-order helicity amplitudes and cross sections for arbitrary scattering processes within the standard electroweak theory and QCD. The algorithm for the amplitude computation, HELAC, exploits the virtues of the Dyson-Schwinger equations. The phase-space generation algorithm, PHEGAS, constructs all possible kinematical mappings dictated by the amplitude under consideration. Combined with mutichannel self-optimized Monte Carlo integration it results to efficient cross section evaluation.

Comments: 4 pages, LaTeX, to appear in the proceedings of the VII International Workshop on Advanced Computing and Analysis Technics in Physics Research, ACAT 2000, Fermilab, October 16-20, 2000