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

Published

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 10u-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

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 April 20, 2024)
Created May 29, 2007, Updated February 17, 2017