Higher-order corrections for effective field theories

There is currently much effort by phenomenologists and experimentalists alike to constrain new physics contributions using LHC data within the SMEFT framework. Higgs physics is central to this programme, also at future colliders. A dedicated treatment requires, first and foremost, a precise modelling of the SM contributions to benchmark Higgs decay and pro-duction modes. Furthermore, including NLO EW and QCD corrections from dimension-6 SMEFT operators is extremely beneficial, both in order to give a realistic view of the number of operators contributing to a given process, and also to stabilise the dependence on unphysical renormalisation scales. While in recent years the calculation of NLO QCD corrections within SMEFT has developed considerably, EW corrections are still in their infancy, limited to a handful of simple processes at parton level and thus not immediately available for serious analyses of experimental data. This project will
develop a comprehensive tool for modelling Higgs decays within SMEFT, including both EW and QCD corrections originating in the SM and SMEFT to production and decay in phenomenologically relevant channels.
interface this tool to the NNLO accurate description of Higgs boson production in the SHERPA event generator. In addition, this allows its parton level out-put to be subjected to the parton showers and hadronisation modules of the SHERPA framework, allowing for a realistic and experimentally usable description of the fully exclusive final state.