Bounding W-W' mixing with spin asymmetries at RHIC

Understand

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.