We present the first results of a new search for a permanent electric dipole moment of the ${}^{199}\mathrm{Hg}$ atom using a UV laser. Our measurements give $d{(}^{199}\mathrm{Hg})=-(1.06\pm 0.49\pm 0.40)\times {10}^{-28\mathrm{}}e\mathrm{cm}$. We interpret the result as an upper limit $|d{(}^{199}\mathrm{Hg})|<2.1\mathrm{}\times {10}^{-28\mathrm{}}e\mathrm{cm}$ (95% C.L.), which sets new constraints on ${\overline{\theta }}_{\mathrm{QCD}}$, chromo-EDMs of the quarks, and CP violation in supersymmetric models.

• Received 21 November 2000

DOI:https://doi.org/10.1103/PhysRevLett.86.2505