SMEFTsim 3.0 -- a practical guide

TL;DR

SMEFTsim 3.0 is a comprehensive, user-friendly toolkit for automated calculations in the Standard Model Effective Field Theory, enhancing modeling capabilities for Higgs and top quark processes.

Contribution

This paper introduces SMEFTsim 3.0, a new version with improved Higgs production modeling, additional flavor assumptions, and features for linearized SMEFT corrections, facilitating advanced phenomenological studies.

Findings

Enhanced Higgs production modeling in gluon-fusion

Added flavor assumptions for top quark studies

Implemented linearized SMEFT corrections to propagators

Abstract

The SMEFTsim package is designed to enable automated computations in the Standard Model Effective Field Theory (SMEFT), where the SM Lagrangian is extended with a complete basis of dimension six operators. It contains a set of models written in FeynRules and pre-exported to the UFO format, for usage within Monte Carlo event generators. The models differ in the flavor assumptions and in the input parameters chosen for the electroweak sector. The present document provides a self-contained, pedagogical reference that collects all the theoretical and technical aspects relevant to the use of SMEFTsim and it documents the release of version 3.0. Compared to the previous release, the description of Higgs production via gluon-fusion in the SM has been significantly improved, two flavor assumptions for studies in the top quark sector have been added, and a new feature has been implemented, that allows the treatment of linearized SMEFT corrections to the propagators of unstable particles.