Effective Field Theory of Precision Electroweak Physics at One Loop

TL;DR

This paper calculates one-loop effects of dimension-six operators on electroweak precision observables within an effective field theory, revealing weaker bounds on operator coefficients than previously claimed.

Contribution

It provides a consistent one-loop analysis of dimension-six operators in effective field theory, clarifying the bounds on their coefficients and challenging earlier stronger bounds.

Findings

Coefficients are weakly bounded by precision data

Proper EFT handling yields more reliable bounds

Previous stronger bounds are likely incorrect

Abstract

The one loop effects of two dimension-six operators on gauge boson self energies are computed within an effective field theory framework. These self energies are translated into effects on precision electroweak observables, and bounds are obtained on the operator coefficients. The effective field theory framework allows for the divergences that arise in the loop calculations to be properly handled, and for unambiguous bounds on the coefficients to be obtained. We find that the coefficients are only weakly bounded, in contrast to previous calculations that obtained much stronger bounds. We argue that the results of these previous calculations are specious.