Contribution of the Weinberg-type Operator to atomic and nuclear electric dipole moments

Abstract

The contribution of the CP violating three-gluon Weinberg operator, $\frac{1}{3!}w{f}^{abc}{ϵ}^{\nu \rho \alpha \beta }{G}_{\mu \nu }^a{G}_{\alpha \beta }^b{G}_{\rho }^{c\mu }$, to the atomic and nuclear EDMs is estimated using QCD sum rules. After calculating the transition matrix element between the pion and the vacuum through the Weinberg operator, we obtain the long-range CP-odd nuclear force by determining the isovector CP-odd pion-nucleon vertex, using chiral perturbation theory at NLO. The EDMs of ${}^{199}$Hg, ${}^{129}$Xe, ${}^{225}$Ra, ${}^2$H, and ${}^3$He are finally given including comprehensive uncertainty analysis. While the leading contribution of the ${}^{199}$Hg EDM is given by the intrinsic nucleon EDM, that of ${}^{129}$Xe atom may be dominated by the one-pion exchange CP-odd nuclear force generated by the Weinberg operator. From current experimental data of the ${}^{199}$Hg atomic EDM, we obtain an upper limit on the Weinberg operator magnitude of $\left|w\right|<4\times 10^{-10}{\mathrm{GeV}}^{-2}$ if we assume that it is the only source of CP violation at the scale $\mu =1$ TeV.

Comments: 25 pages, 8 figures