Nucleon electric dipole moment from polarized deep inelastic scattering

TL;DR

This paper estimates the proton and neutron electric dipole moments induced by the Weinberg operator using polarized deep inelastic scattering, providing a potentially more accurate calculation that is smaller than previous QCD sum rule estimates.

Contribution

It establishes a connection between the Weinberg operator and twist-four corrections in deep inelastic scattering, offering a novel numerical estimate of nucleon EDMs.

Findings

The estimated EDMs are smaller than previous QCD sum rule estimates.

The paper clarifies the role of twist-four corrections in EDM calculations.

Provides a new approach to evaluate nucleon EDMs from CP-odd operators.

Abstract

In a previous paper \cite{Hatta:2020ltd}, we have pointed out the connection between the $CP$-odd three-gluon (Weinberg) operator and certain twist-four corrections in polarized deep inelastic scattering. Based on this observation, we give a numerical estimate of the electric dipole moment of the proton and neutron induced by the Weinberg operator. Our result is smaller than the previous estimates based on QCD sum rules by a factor of about 3 or more.