Theoretical developments in the SMEFT at dimension-8 and beyond

TL;DR

This paper reviews recent theoretical progress in the SMEFT framework at dimension-8 and higher, including operator basis construction, all-orders results, renormalization, and phenomenological implications for experiments.

Contribution

It provides a comprehensive overview of the latest theoretical developments in SMEFT at higher dimensions, including new operator bases and phenomenological effects.

Findings

Complete operator bases for dimension-8 and -9 SMEFT Lagrangians

Potential for all-orders results in certain observables

New phenomenological effects at dimension-8

Abstract

In this contribution to the Snowmass 2021 process we review theoretical developments in the Standard Model Effective Field Theory (SMEFT) with a focus on effects at the dimension-8 level and beyond. We review the theoretical advances that led to the complete construction of the operator bases for the dimension-8 and dimension-9 SMEFT Lagrangians. We discuss the possibility of obtaining all-orders results in the $1/\Lambda$ expansion for certain SMEFT observables as well as the current status of renormalization group running and implications for positivity, and briefly present the on-shell approach to constructing SMEFT amplitudes. Finally we present several new phenomenological effects that first arise at dimension-8 and discuss the impact of these terms on experimental analyses.