# ewN2HDECAY - A program for the Calculation of Electroweak One-Loop Corrections to Higgs Decays in the Next-to-Minimal Two-Higgs-Doublet Model Including State-of-the-Art QCD Corrections

## TL;DR

ewN2HDECAY is a new computational tool that calculates electroweak one-loop corrections to Higgs decays in the N2HDM, combining them with advanced QCD corrections for precise phenomenological analysis.

## Contribution

The paper introduces ewN2HDECAY, a program that computes complete electroweak one-loop corrections in the N2HDM, integrating them with existing QCD corrections for the first time.

## Key findings

- Provides high-precision decay width calculations for N2HDM Higgs bosons.
- Enables analysis of electroweak correction impacts and theoretical uncertainties.
- Offers a flexible renormalization scheme implementation for phenomenological studies.

## Abstract

We present in this paper our new program package ewN2HDECAY for the calculation of the partial decay widths and branching ratios of the Higgs bosons of the Next-to-Minimal 2-Higgs Doublet Model (N2HDM). The N2HDM is based on a general CP-conserving 2HDM which is extended by a real scalar singlet field. The program computes the complete electroweak one-loop corrections to all non-loop-induced two-body on-shell Higgs boson decays in the N2HDM and combines them with the state-of-the-art QCD corrections that are already implemented in the existing program N2HDECAY. Most of the independent input parameters of the electroweak sector of the N2HDM are renormalized in an on-shell scheme. The soft-$\mathbb{Z}_2$-breaking squared mass scale $m_{12}^2$ and the vacuum expectation value $v_S$ of the $SU(2)_L$ singlet field, however, are renormalized with $\overline{\text{MS}}$ conditions, while for the four scalar mixing angles $\alpha _i$ ($i=1,2,3$) and $\beta$ of the N2HDM, several different renormalization schemes are applied. By giving out the leading-order and the loop-corrected partial decay widths separately from the branching ratios, the program ewN2HDECAY not only allows for phenomenological analyses of the N2HDM at highest precision, it can also be used for a study of the impact of the electroweak corrections and the remaining theoretical uncertainty due to missing higher-order corrections based on a change of the renormalization scheme. The input parameters are then consistently calculated with a parameter conversion routine when switching from one renormalization scheme to the other. The latest version of the program ewN2HDECAY can be downloaded from the URL \href{https://github.com/marcel-krause/ewN2HDECAY}{https://github.com/marcel-krause/ewN2HDECAY}.