Weinberg operator contribution to the nucleon electric dipole moment in the quark model

クォーク模型による核子電気双極モーメントへのワインバーグ演算子の寄与

山中 長閑*; 肥山 詠美子

Yamanaka, Nodoka*; Hiyama, Emiko

We evaluate the contribution of the -violating gluon chromo-electric dipole moment (the so-called Weinberg operator, denoted as ) to the electric dipole moment (EDM) of nucleons in the nonrelativistic quark model. The -odd interquark potential is modeled by the perturbative one-loop level gluon exchange generated by the Weinberg operator with massive quarks and gluons. The nucleon EDM is obtained by solving the nonrelativistic Schrdinger equation of the three-quark system using the Gaussian expansion method. It is found that the resulting nucleon EDM, which may reasonably be considered as the irreducible contribution, is smaller than the one obtained after " rotating" the anomalous magnetic moment using the -odd mass calculated with QCD sum rules. We estimate the total contribution to be = 20 MeV and = - 18 MeV with 60% of theoretical uncertainty.