'carlomat', version 2 of the program for automatic computation of lowest order cross sections

TL;DR

The paper introduces version 2 of 'carlomat', an automated tool for calculating lowest order cross sections of multiparticle reactions, with significant improvements in phase space generation, interface, and physics modeling.

Contribution

It presents substantial updates to 'carlomat', including unified phase space parametrization, enhanced interfaces, and expanded physics models, enabling more accurate and versatile cross section computations.

Findings

Enhanced phase space generation for similar topology diagrams

Added interface to parton density functions

Improved color matrix computation and physics models

Abstract

Version 2 of 'carlomat', a program for automatic computation of the lowest order cross sections of multiparticle reactions, is described. The substantial modifications with respect to version 1 of the program include: generation of a single phase space parametrization for the Feynman diagrams of the same topology, an interface to parton density functions, improvement of the color matrix computation, the Cabibbo-Kobayashi-Maskawa mixing in the quark sector, the effective models including scalar electrodynamics, the Wtb interaction with operators of dimension up to 5 and a general top-higgs coupling. Moreover, some minor modifications have been made and several bugs in the program have been corrected.