Consistent constraints on the Standard Model Effective Field Theory

TL;DR

This paper provides a comprehensive global analysis of the Standard Model Effective Field Theory by incorporating diverse experimental data and developing a theory error metric to refine parameter constraints at high precision.

Contribution

It introduces a new framework for including theoretical errors in EFT constraints, leading to more accurate bounds on parameters and a modified S,T analysis.

Findings

Constraints on EFT parameters are relaxed when theory errors are included.

A new theory error metric improves the reliability of high-precision bounds.

The analysis incorporates data from multiple collider experiments and low energy measurements.

Abstract

We develop the global constraint picture in the (linear) effective field theory generalisation of the Standard Model, incorporating data from detectors that operated at PEP, PETRA, TRISTAN, SpS, Tevatron, SLAC, LEPI and LEP II, as well as low energy precision data. We fit one hundred and three observables. We develop a theory error metric for this effective field theory, which is required when constraints on parameters at leading order in the power counting are to be pushed to the percent level, or beyond, unless the cut off scale is assumed to be large, $\Lambda \gtrsim \, 3 \, {\rm TeV}$. We more consistently incorporate theoretical errors in this work, avoiding this assumption, and as a direct consequence bounds on some leading parameters are relaxed. We show how an $\rm S,T$ analysis is modified by the theory errors we include as an illustrative example.