2HDMC - Two-Higgs-Doublet Model Calculator

TL;DR

2HDMC addresses the need for a flexible, public tool to study a general CP-conserving two-Higgs-doublet model. It provides multiple parametrizations of the Higgs potential, a highly configurable Yukawa sector, a comprehensive tree-level decay library (including loop-induced modes), and robust theoretical and experimental constraint checks, all within a modular C++ framework. Key contributions include basis-parameter conversion, Yukawa sector customization with FCNC control via Z2 symmetries, and standardized interfaces (LesHouches, HiggsBounds, NMSSMTools, MadGraph) for interoperability and phenomenological studies. This tool enables precise phenomenological explorations and cross-code consistency checks, facilitating constraints on 2HDM parameter spaces and collider phenomenology.

Abstract

This manual describes the public code 2HDMC which can be used to perform calculations in a general, CP-conserving, two-Higgs-doublet model (2HDM). The program features simple conversion between different parametrizations of the 2HDM potential, a flexible Yukawa sector specification with choices of different Z_2-symmetries or more general couplings, a tree-level decay library including all two-body - and some three-body - decay modes for the Higgs bosons, and the possibility to calculate observables of interest for constraining the 2HDM parameter space, as well as theoretical constraints from positivity and unitarity. The latest version of the 2HDMC code and full documentation is available from: http://www.isv.uu.se/thep/MC/2HDMC