Bounding W-W' mixing with spin asymmetries at RHIC

TL;DR

This paper proposes a new method to measure or bound the mixing between W and W' bosons using spin asymmetries at RHIC, providing a model-independent approach to explore potential new physics beyond the Standard Model.

Contribution

It introduces a novel, model-independent technique to probe W-W' mixing through spin asymmetries, sensitive to both real and imaginary parts of the coupling.

Findings

Demonstrates the feasibility of measuring the mixing at RHIC.

Provides a method to bound the complex coupling without assumptions on new physics.

Enhances the sensitivity to CP-violating effects in W-W' mixing.

Abstract

The W boson can obtain a small right-handed coupling to quarks and leptons through mixing with a hypothetical W' boson that appears in many extensions of the Standard Model. Measuring or even bounding this coupling to the light quarks is very challenging. Only one model independent bound on the absolute value of the complex mixing parameter has been obtained to date. Here we discuss a method sensitive to both the real and CP-violating imaginary parts of the coupling, independent of assumptions on the new physics, and demonstrate quantitatively the feasibility of its measurement at RHIC.