CERN Accelerating science

HELAC-Onia

HELAC-Onia is an automatic matrix element generator for the calculation of the heavy quarkonium helicity amplitudes in the framework of nonrelativistic QCD factorization based on the public program HELAC-PHEGAS. The program is able to calculate helicity amplitudes of multiply P-wave quarkonium state production at hadron colliders and electron-positron colliders by including new P-wave off-shell currents. Besides the high efficiencies in computation of multi-leg processes within the Standard Model, HELAC-Onia is also sufficiently numerical stable in dealing with P-wave quarkonia and P-wave color-octet intermediate states. It provides options of generating hard events, interfacing to PYTHIA 8 and generating histograms with event manipulation.

Compilers

• gfortran
• gcc
• python 2.X

References

• "HELAC-Onia: An automatic matrix element generator for heavy quarkonium physics"
  H.-S. Shao
  Comput.Phys.Commun. 184 (2013) 2562-2570 [arXiv:1212.5293[hep-ph]].
• "HELAC-Onia 2.0: an upgraded matrix-element and event generator for heavy quarkonium physics"
  H.-S. Shao
  Comput.Phys.Commun. 198 (2016) 238-259 [arXiv:1507.03435[hep-ph]].

Downloads

• HELAC-Onia Version 2.7.6
• HELAC-Onia on HELAC-PHEGAS webpage
• nCTEQ15 Pb grid for HELAC-Onia
• EPPS16 Pb grid for HELAC-Onia
• HELAC-Onia Web Generation (preliminary)

Contact

If you have questions, comments, suggestions or bug reports, please email to huasheng.shao_AT_lpthe.jussieu.fr.