Quark–hadron duality constraints on γZ box corrections to parity-violating elastic scattering

摘要

We examine the interference γZ 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 ≈ 1 ? GeV 2 . Assuming that a similar behavior also holds for the γZ proton structure functions, we find that duality constrains the γZ box correction to the proton's weak charge to be ? e □ γ Z V = ( 5.4 ± 0.4 ) × 10 ? 3 at the kinematics of the Q weak experiment. Within the same model we also provide estimates of the γZ corrections for future parity-violating experiments, such as MOLLER at Jefferson Lab and MESA at Mainz.