HELAC-Onia: An automatic matrix element generator for heavy quarkonium physics

Abstract
By the virtues of the Dyson-Schwinger equations, we upgrade the published code HELAC to be capable to calculate the heavy quarkonium helicity amplitudes in the framework of NRQCD factorization, which we dub HELAC-Onia. We rewrote the original HELAC to make the new program be able to calculate helicity amplitudes of multi P-wave quarkonium states production at hadron colliders and electron-positron colliders by including new P-wave off-shell currents. Therefore, besides the high efficiencies i...

Title of program: HELAC-Onia.
Catalogue Id: AEPR_v1_0

Nature of problem
An important way to explore the law of the nature is to investigate the heavy quarkonium physics at B factories and hadron colliders. However, its production mechanism is still unclear, though NRQCD can explain its decay mechanism in a sufficiently satisfactory manner. The substantial K-factor in heavy quarkonium production processes also implies that the associated production of quarkonium and a relatively large number of particles may play a crucial role in unveiling its production mechanism.

Versions of this program held in the CPC repository in Mendeley Data
AEPR_v1_0; HELAC-Onia.; 10.1016/j.cpc.2013.05.023
AEPR_v2_0; HELAC-Onia 2.0; 10.1016/j.cpc.2015.09.011

This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2019)