# The Standard Model as an Effective Field Theory

## TL;DR

This paper reviews how effective field theories like SMEFT and HEFT are used to interpret LHC measurements of the Standard Model, especially the Higgs boson, enabling systematic and consistent analysis of experimental data.

## Contribution

It provides a pedagogical overview of EFT construction, discusses historical and future applications in Higgs physics, and reviews recent advances and challenges in EFT methods for LHC data analysis.

## Key findings

- EFT frameworks enable consistent interpretation of Higgs measurements.
- Systematic improvements in EFT approaches are possible with higher order corrections.
- Challenges in EFT application to LHC data are identified and discussed.

## Abstract

Projecting measurements of the interactions of the known Standard Model (SM) states into an effective field theory (EFT) framework is an important goal of the LHC physics program. The interpretation of measurements of the properties of the Higgs-like boson in an EFT allows one to consistently study the properties of this state, while the SM is allowed to eventually break down at higher energies. In this review, basic concepts relevant to the construction of such EFTs are reviewed pedagogically. Electroweak precision data is discussed as a historical example of some importance to illustrate critical consistency issues in interpreting experimental data in EFTs. A future precision Higgs phenomenology program can benefit from the projection of raw experimental results into consistent field theories such as the SM, the SM supplemented with higher dimensional operators (the SMEFT) or an Electroweak chiral Lagrangian with a dominantly $J^P = 0^+$ scalar (the HEFT). We discuss the developing SMEFT and HEFT approaches, that are consistent versions of such EFTs, systematically improvable with higher order corrections, and comment on the pseudo-observable approach. We review the challenges that have been overcome in developing EFT methods for LHC studies, and the challenges that remain.