Renormalization group evolution of the universal theories EFT

TL;DR

This paper analyzes how renormalization group evolution affects universal theories within the Standard Model effective field theory, impacting precision electroweak and Higgs data interpretations.

Contribution

It provides a detailed renormalization group analysis of universal theories in SMEFT and discusses how RG flow induces nonuniversal effects at the electroweak scale.

Findings

RG evolution can cause universal theories to become nonuniversal at low energies.

Additional prescriptions are needed to define universal parameters at the electroweak scale.

RG effects influence the interpretation of precision electroweak and Higgs data.

Abstract

The conventional oblique parameters analyses of precision electroweak data can be consistently cast in the modern framework of the Standard Model effective field theory (SMEFT) when restrictions are imposed on the SMEFT parameter space so that it describes universal theories. However, the usefulness of such analyses is challenged by the fact that universal theories at the scale of new physics, where they are matched onto the SMEFT, can flow to nonuniversal theories with renormalization group (RG) evolution down to the electroweak scale, where precision observables are measured. The departure from universal theories at the electroweak scale is not arbitrary, but dictated by the universal parameters at the matching scale. But to define oblique parameters, and more generally universal parameters at the electroweak scale that directly map onto observables, additional prescriptions are needed for the treatment of RG-induced nonuniversal effects. We perform a RG analysis of the SMEFT description of universal theories, and discuss the impact of RG on simplified, universal-theories-motivated approaches to fitting precision electroweak and Higgs data.