Improved Limits on Variation of the Fine Structure Constant and Violation of Local Position Invariance

Published

May 29, 2007

Author(s)

Tara M. Fortier, Neil Ashby, James C. Bergquist, Marie Delaney, Scott A. Diddams, Thomas P. Heavner, Leo W. Hollberg, Wayne M. Itano, Steven R. Jefferts, K Kim, Windell Oskay, Thomas E. Parker, Jon H. Shirley, Jason Stalnaker, Filippo Levi, Luca Lorini

Abstract

We report tests of Local Position Invariance (LPI) and constancy of fundamental constants from measurements of the frequency ratio of the 282-nm ¹⁹⁹Hg⁺ optical clock transition to the ground-state hyperfine splitting in ¹³³Cs. Analysis of the frequency ratio, extending over six years at NIST, is used to place a limit on the fractional variation of the two clocks of <5.8 x 10 ^-6 per change in normalized solar gravitational potential, and a limit on fractional variation of the fine structure constant at a/a <1.3 x 10^-16 yr^-1 , assuming invariance of other fundamental constants. Comparison of our results with those previously reported for the absolute optical frequency measurements of ¹⁷¹Yb⁺ versus other ¹³³Cs standard yields a coupled constraint of -0.04 x 10^-15 <a/a <0.46 x 10 ^-15 yr^-1 and -2.39 x 10 ^-15 <d/d ln ^υCs/^{υB <0.47 x 10}u-15^yr^-1.

Proceedings Title

Proc. 2007 Joint Mtg. IEEE Intl. Freq. Cont. Symp. and EFTF Conf.

Conference Dates

May 27-June 1, 2007

Conference Location

Geneva, CH

Pub Type

Conferences

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Local Download

Keywords

ces, ions, spec

Citation

Fortier, T. , Ashby, N. , Bergquist, J. , Delaney, M. , Diddams, S. , Heavner, T. , Hollberg, L. , Itano, W. , Jefferts, S. , Kim, K. , Oskay, W. , Parker, T. , Shirley, J. , Stalnaker, J. , Levi, F. and Lorini, L. (2007), Improved Limits on Variation of the Fine Structure Constant and Violation of Local Position Invariance, Proc. 2007 Joint Mtg. IEEE Intl. Freq. Cont. Symp. and EFTF Conf., Geneva, CH, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50561 (Accessed October 7, 2024)