CompHEP - a package for evaluation of Feynman diagrams and integration over multi-particle phase space. User's manual for version 33
A. Pukhov, E. Boos, M. Dubinin, V. Edneral, V. Ilyin, D. Kovalenko, A. Kryukov, V. Savrin, S. Shichanin, A. Semenov
TL;DR
CompHEP version 33 presents a comprehensive framework for automating tree-level calculations of particle decays and collisions, linking Lagrangian input to final distributions via a symbolic-numerical pipeline. It combines a GUI/text-interface for model selection, diagram generation, and symbolic manipulation with a robust Monte Carlo numerics (Vegas) and optional Simpson integration, including an event generator workflow. The manual documents model definition (parameters, constraints, particles, vertices), ghost-field implementations, and multi-format outputs (LaTeX, Reduce/Mathematica, Fortran/C), along with LanHEP compatibility for SUSY models. Its design emphasizes automation, modularity, and cross-checking through Reduce and external tools, enabling users to explore standard and beyond-Standard-Model scenarios efficiently. The practical impact is a versatile platform for rapid, reproducible computation of cross sections, decay widths, and event samples at tree level, with broad support for phase-space mapping, QCD-scale handling, and ghost-conserving gauge-invariant calculations.
Abstract
CompHEP is a package for automatic calculations of elementary particle decay and collision properties in the lowest order of perturbation theory (the tree approximation). The main idea prescribed into the CompHEP is to make available passing on from the Lagrangian to the final distributions effectively with a high level of automation.