Dimension-8 Operators in the Standard Model Effective Field Theory

Abstract

We present a complete basis of dimension-8 operators in the Standard Model Effective Field Theory. Attention is paid to operators that vanish in the absence of flavor structure. There are dimension-8 SMEFT 44,807 operators. We also briefly discuss a few aspects of phenomenology involving dimension-8 operators, including light-by-light scattering and electroweak precision data.

Comments: 50 pages, 21 tables; v6: minor update, $ϵ{\tau }^I$ (${\tau }^Iϵ$) goes with a pair of $SU(2{)}_w$ doublet (anti-)fermions