CalcHEP 2.3: MSSM, structure functions, event generation, batchs, and generation of matrix elements for other packages
Alexander Pukhov
TL;DR
CalcHEP 2.3 extends automated tree-level calculations with MSSM support via the Les Houches Accord, enhanced parton-distribution interfaces, and direct event generation with PYTHIA. It introduces comprehensive batch processing, improved model-table tooling, and the ability to export matrix elements for external codes, enabling seamless integration into broader phenomenology workflows. The combination of MSSM spectrum interfaces (Suspect/Isajet/SoftSusy/SPHENO), PDF handling (PDFLIB/CTEQ/MRST), and VEGAS-based event generation significantly broadens CalcHEP's applicability to collider phenomenology and relic-density computations. Collectively, these features improve automation, interoperability, and scalability for particle-physics calculations at tree level, from model definition to event-level predictions.
Abstract
CalcHEP is a package for computation of Feynman diagrams and integration over multi-particle phase space. The main idea prescribed into CalcHEP is to make available passing on from Lagrangians to the final distributions effectively with a high level of automation. This article presents new options of CalcHEP available in version 2.3. They are a) MSSM model with different SUGRA scenarios, b) interface with PDFLIB and implementation of new MRST/CTEQ structure functions, c) realization of approach to structure functions for models with diagonal CKM, d) generation of events and interface with PYTHIA, e) calculations in non-interactive (batch) regime, f)generation of code of different matrix elements for other programs, g) many new interface facilities.