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[Licence| Download | New Version Template] aepr_v2_0.tar.gz(16636 Kbytes)
Manuscript Title: HELAC-Onia 2.0: an upgraded matrix-element and event generator for heavy quarkonium physics
Authors: Hua-Sheng Shao
Program title: HELAC-Onia 2.0
Catalogue identifier: AEPR_v2_0
Distribution format: tar.gz
Journal reference: Comput. Phys. Commun. 198(2016)238
Programming language: Python, Fortran 77, Fortran 90, C++.
Operating system: Unix-like platform.
Keywords: Heavy quarkonium, NRQCD, Monte Carlo simulation.
Classification: 4.4, 11.1, 11.2, 11.5.

External routines: LHAPDF

Does the new version supersede the previous version?: Yes

Nature of problem:
Heavy quarkonium production processes provide an important way to investigate QCD in its poorly known non-perturbative regime. Its production mechanism has been attracted extensive interests from the high-energy physics community in decades. The qualitative and quantitative description of heavy-quarkonium production requires complex perturbative computations for high-multiplicity processes in the framework of the well established non-relativistic effecitive theory, NRQCD, and reliable Monte Carlo simulations to repreduce the collider enviroment.

Solution method:
Based on a recursion relation, the program is able to calculate the helicity ampltiudes of the high-multiplicity heavy-qurkonium-production processes. Several modules are also designed for dedicated simulations:
  1. The code has been interfaced with the parton shower Monte Carlo programs;
  2. A decay module to let heavy quarkonia decay with correct spin-correlations has been implemented;
  3. The code estimates the theoretical uncertainties and analyzes the generated events on the fly;
  4. The code is compilant with multi-threading/multi-core usage or cluster processors.

Reasons for new version:
Improved and expanded functionalities.

Summary of revisions:
Many new features were added and several important bugs were fixed. The new features extend the range of the physical applications. With the new interface, it also helps to improve the user-friendliness of the program.

Running time:
It depends on the process to be calculated and the required accuracy.