We examine the sensitivity of electric dipole moments (EDMs) to new CP-violating physics in a hidden (or dark) sector, neutral under the Standard Model (SM) gauge groups, and coupled via renormalizable portals. In the absence of weak sector interactions, we show that the electron EDM can be induced purely through the gauge kinetic mixing portal, but requires five loops, and four powers of the kinetic mixing parameter ϵ. Allowing weak interactions, and incorporating the Higgs and neutrino portals, we show that the leading contributions to de arise at two-loop order, with the main source of CP-violating being in the interaction of dark Higgs and heavy singlet neutrinos. In such models, EDMs can provide new sensitivity to portal couplings that is complementary to direct probes at the intensity frontier or high energy colliders.
Bibliographical noteFunding Information:
The work of S.O, M. P. and A. R. is supported in part by NSERC, Canada, and research at the Perimeter Institute is supported in part by the Government of Canada through NSERC and by the Province of Ontario through MEDT. APPENDIX A:
© 2019 authors. Published by the American Physical Society.