Finite-Q^2 corrections to parity-violating DIS

TL;DR

This paper analyzes finite-Q^2 effects in parity-violating deep inelastic scattering, emphasizing their importance for precise extraction of parton distribution ratios and potential signals of new physics.

Contribution

It provides a detailed study of subleading kinematical and longitudinal corrections in PVDIS asymmetries, crucial for accurate interpretation of experimental data.

Findings

Finite-Q^2 effects significantly impact d/u ratio extraction at large x.

Corrections are essential for identifying charge symmetry violation.

Asymmetries depend on u and d helicity distributions at large x.

Abstract

Parity-violating deep inelastic scattering (PVDIS) has been proposed as an important new tool to extract the flavor and isospin dependence of parton distributions in the nucleon. We discuss finite-Q^2 effects in PVDIS asymmetries arising from subleading kinematical corrections and longitudinal contributions to the photon-Z interference. For the proton, these need to be accounted for in order to accurately extract the d/u ratio at large x; for the deuteron they are important to consider when searching for evidence of charge symmetry violation in parton distributions or signals for physics beyond the standard model. We further explore the dependence of PVDIS asymmetries for polarized targets on the u and d helicity distributions at large x.