Quark-hadron duality constraints on \gamma Z box corrections to parity-violating elastic scattering

TL;DR

This paper investigates how quark-hadron duality influences the b3Z box corrections in parity-violating electron-proton scattering, providing constrained estimates relevant for precision tests of the Standard Model.

Contribution

It introduces a duality-based approach to constrain b3Z box corrections, offering new estimates for the proton's weak charge and future experiments.

Findings

b3Z box correction constrained to (5.4 1 0.4) imes 10^{-3} at Q_{ ext{weak}}.

Duality assumptions reduce uncertainties in b3Z correction estimates.

Provides predictions for upcoming parity-violating experiments like MOLLER and MESA.

Abstract

We examine the interference \gamma Z box corrections to parity-violating elastic electron--proton scattering in the light of the recent observation of quark-hadron duality in parity-violating deep-inelastic scattering from the deuteron, and the approximate isospin independence of duality in the electromagnetic nucleon structure functions down to Q^2 \approx 1 GeV^2. Assuming that a similar behavior also holds for the \gamma Z proton structure functions, we find that duality constrains the \gamma Z box correction to the proton's weak charge to be \Re e\, \square_{\gamma Z}^V = (5.4 \pm 0.4) \times 10^{-3} at the kinematics of the Q_{\text{weak}} experiment. Within the same model we also provide estimates of the \gamma Z corrections for future parity-violating experiments, such as MOLLER at Jefferson Lab and MESA at Mainz.