Reevaluation of Neutron Electric Dipole Moment with QCD Sum Rules

TL;DR

This paper reevaluates the neutron electric dipole moment using QCD sum rules, providing updated limits on CP-violating operators with lattice input parameters and discussing methodological robustness.

Contribution

It offers a detailed reanalysis of the neutron EDM with improved sum rule techniques and incorporates lattice QCD inputs for more reliable constraints.

Findings

Robust OPE calculation with a specific neutron interpolating field

Derived conservative limits on CP-violating operators

Detailed derivation of the sum rules

Abstract

We study the neutron electric dipole moment in the presence of the CP-violating operators up to the dimension five in terms of the QCD sum rules. It is found that the OPE calculation is robust when exploiting a particular interpolating field for neutron, while there exist some uncertainties on the phenomenological side. By using input parameters obtained from the lattice calculation, we derive a conservative limit for the contributions of the CP violating operators. We also show the detail of the derivation of the sum rules.