Higgs Decays at NLO in the SMEFT

TL;DR

This paper provides precise NLO predictions for Higgs decays within the SMEFT framework, including two- and three-body decays, and introduces a publicly available Monte Carlo tool for future collider analyses.

Contribution

It presents the first comprehensive NLO calculations for multiple Higgs decay channels in SMEFT, enhancing the accuracy of Higgs property measurements at colliders.

Findings

NLO electroweak corrections significantly impact Higgs decay rates.

The NEWiSH Monte Carlo program facilitates detailed collider studies.

Results improve the precision of Higgs property extractions at future experiments.

Abstract

The calculation of precise predictions for Higgs decays is a necessary ingredient for determining Higgs properties at the LHC and future colliders. We compute all two- and three-body Higgs decays at next-to-leading order (NLO) in both QCD and electroweak interactions using the dimension-6 Standard Model Effective Field Theory (SMEFT). Results for four-body Higgs decays that are accurate to NLO QCD/electroweak order in the SMEFT are obtained using the narrow width approximation. Our results are contained in a flexible Monte Carlo program, NEWiSH, that is publicly available and we illustrate the impact of the NLO electroweak corrections for HL-LHC, Tera-Z, and Higgstrahlung projections.