H-COUP: A program for one-loop corrected Higgs boson couplings in non-minimal Higgs sectors

Abstract

We describe a numerical calculation tool H-COUP33The webpage of H-COUP is given in http://www-het.phys.sci.osaka-u.ac.jp/~kanemu/HCOUP_HP1013/HCOUP_HP.html, where one can download the set of source files of H-COUP_1.0. written in Fortran, which provides one-loop electroweak corrected vertices for the discovered Higgs boson h(125) in various Higgs sectors. The renormalization is based on the improved on-shell scheme without gauge dependence. In the first version H-COUP_1.0, the following models are included, namely, the Higgs singlet model, four types (Type-I, Type-II, Type-X, Type-Y) of two Higgs doublet models with a softly-broken Z2 symmetry and the inert doublet model. We first briefly introduce these models and then explain how to install and run this tool in an individual machine. A sample of numerical outputs is provided for user information. Program summaryProgram title: H-COUPProgram Files doi: http://dx.doi.org/10.17632/f88szmrj5x.1Licensing provisions: GPLv3Programming language: Fortran90Nature of problem: One-loop electroweak corrected vertices for the discovered Higgs boson h(125) are numerically calculated in the Higgs singlet model, four types (Type-I, Type-II, Type-X, Type-Y) of two Higgs doublet models with a softly-broken Z2 symmetry and the inert doublet model. The renormalization is based on the improved on-shell scheme without gauge dependence. Loop induced decay rates, i.e., h→γγ, h→Zγ and h→gg are also computed in these extended Higgs sectors at leading order.Solution method: All one-loop integrals for one-, two- and three-point functions are analytically expressed by using Passarino–Veltman functions in a systematic way, and their numerical values are calculated through the LoopTools. One-loop corrected h(125) vertices are then numerically provided in terms of form factors which are obtained by decomposing their Lorentz structure.Additional comments including restrictions and unusual features: In the version 1.0, QCD corrections are not included in the calculation of the h(125) vertices as well as the loop induced decay rates. In addition, the total width, decay branching ratios and cross sections are not outputted automatically. Details of these issues are described in Sec. VII of this manual.