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arXiv · 0801.1874

New Limits on Coupling of Fundamental Constants to Gravity Using $^{87}$Sr Optical Lattice Clocks

S. Blatt·A. D. Ludlow·G. K. Campbell·J. W. Thomsen·T. Zelevinsky·M. M. Boyd·J. Ye·X. Baillard·M. Fouché·R. Le Targat·A. Brusch·P. Lemonde·M. Takamoto·F. -L. Hong·H. Katori·V. V. Flambaum
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Abstract

The $^1\mathrm{S}_0$-$^3\mathrm{P}_0$ clock transition frequency $ν_\text{Sr}$ in neutral $^{87}$Sr has been measured relative to the Cs standard by three independent laboratories in Boulder, Paris, and Tokyo over the last three years. The agreement on the $1\times 10^{-15}$ level makes $ν_\text{Sr}$ the best agreed-upon optical atomic frequency. We combine periodic variations in the $^{87}$Sr clock frequency with $^{199}$Hg$^+$ and H-maser data to test Local Position Invariance by obtaining the strongest limits to date on gravitational-coupling coefficients for the fine-structure constant $α$, electron-proton mass ratio $μ$ and light quark mass. Furthermore, after $^{199}$Hg$^+$, $^{171}$Yb$^+$ and H, we add $^{87}$Sr as the fourth optical atomic clock species to enhance constraints on yearly drifts of $α$ and $μ$.

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S. Blatt, A. D. Ludlow, G. K. Campbell, J. W. Thomsen, T. Zelevinsky, M. M. Boyd, J. Ye, X. Baillard, M. Fouché, R. Le Targat, A. Brusch, P. Lemonde, M. Takamoto, F. -L. Hong, H. Katori, V. V. Flambaum. 2008-04-29. New Limits on Coupling of Fundamental Constants to Gravity Using $^{87}$Sr Optical Lattice Clocks. https://doi.org/10.1103/physrevlett.100.140801

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