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arXiv · 1205.5022

New Limits on Local Lorentz Invariance in Mercury and Cesium

S. K. Peck·D. K. Kim·D. Stein·D. Orbaker·A. Foss·M. T. Hummon·L. R. Hunter
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Abstract

We report new bounds on Local Lorentz Invariance (LLI) violation in Cs and Hg. The limits are obtained through the observation of the the spin- precession frequencies of 199Hg and 133Cs atoms in their ground states as a function of the orientation of an applied magnetic field with respect to the fixed stars. We measure the amplitudes of the dipole couplings to a preferred direction in the equatorial plane to be 19(11) nHz for Hg and 9(5) microHz for Cs. The upper bounds established here improve upon previous bounds by about a factor of four. The improvement is primarily due to mounting the apparatus on a rotating table. New bounds are established on several terms in the standard model extension including the first bounds on the spin-couplings of the neutron and proton to the z direction, <7e-30 GeV and <7e-29 GeV, respectively.

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S. K. Peck, D. K. Kim, D. Stein, D. Orbaker, A. Foss, M. T. Hummon, L. R. Hunter. 2012-05-22. New Limits on Local Lorentz Invariance in Mercury and Cesium. https://doi.org/10.1103/physreva.86.012109

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