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The authors reexamine the form of the expression used to extract the nucleon EDM from lattice QCD calculations and discover a subtle additional subtraction due to mixing between form factors. They check their claim by comparing with a different method to compute the EDM. Applying their correction to previous computations they obtain more consistent results, albeit now all consistent with a vanishing EDM within errors.
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Abramczyk et al. (2017) studied this question.
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