Ward Identities for the Standard Model Effective Field Theory

TL;DR

This paper derives basis-independent Ward identities for the Standard Model Effective Field Theory using the background field method, providing symmetry constraints that influence perturbative and power-counting expansions.

Contribution

It introduces a geometric approach and real representations to derive basis-independent Ward identities for the SMEFT, enhancing understanding of its symmetry structure.

Findings

Derived basis-independent Ward identities for SMEFT

Established symmetry constraints on perturbative expansions

Provided a geometric framework for field connections

Abstract

We derive Ward identities for the Standard Model Effective Field Theory using the background field method. The resulting symmetry constraints on the Standard Model Effective Field Theory are basis independent, and constrain the perturbative and power-counting expansions. A geometric description of the field connections, and real representations for the $\rm SU(2)_L \times U(1)_Y$ generators, underlies the derivation.