Reevaluation of Neutron Electric Dipole Moment with QCD Sum Rules
  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. 
Junji Hisano, Jeong Yong Lee, Natsumi Nagata, and Yasuhiro Shimizu
hep-ph