PT4 - Variation of the fundamental constants, violation of the fundamental symmetries and dark matter |
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Speaker |
Guéna, Jocelyne |
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Coauthors |
Guéna, Jocelyne; Abgrall, Michel; Hees, Adrien; Le Targat, Rodolphe; Lodewyck, Jérôme; De Sarlo, Luigi; Pottie, Paul-Eric; Le Coq, Yann; Wolf, Peter; Bize, Sebastien |
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Searching for Variations of Fundamental Constants and Dark Matter using an Atomic Clock Ensemble |
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Abstract |
The ratio of two atomic transition frequencies is by definition independent of the unit of frequency and therefore its value depends only on fundamental constants such as the fine-structure constant alpha or fundamental properties of particles like e.g. the electron mass. Repeated measurements of frequency ratios performed in laboratory, with suitable atomic structure calculations, are therefore a direct test of the present-day stability of constants with respect to space-time and, via the motion of the Earth, gravitational potential. Such tests are independent from any cosmological models and complement astrophysical tests. At LNE-SYRTE we operate an ensemble of atomic clocks both in the microwave (hyperfine transition in the ground state of 133Cs and 87Rb) and in the optical part of the spectrum (1S0 - 3P0 in 87Sr and 199Hg) providing for several atomic frequency comparisons [1]. In this talk we will report more specifically on highly accurate Rb/Cs comparisons performed with atomic fountains over more than 15 yr. They provide stringent limits on a possible time variation, or coupling to gravity, of a particular linear combination of constants involving alpha and the quark mass scaled to the QCD mass scale, in addition to a stringent differential redshift test for Rb/Cs [2]. Besides, the results provide improved constraints on the coupling of a putative massive scalar dark matter field to standard matter [3]. We will also present repeated accurate measurements of the frequency ratios Sr/Cs, Hg/Cs, Sr/Rb and Hg/Rb[4][5] which complement similar measurements performed in other laboratories. Prospects for improving such tests using coherent optical fiber links will be mentioned[6]. [1] M. Abgrall et al., C.R. Physique 16, 461-470 (2015) [2] J. Guéna et al., Phys. Rev. Lett. 109, 080801 (2012) [3] A. Hees, J. Guéna, M. Abgrall, S. Bize and P. Wolf, PRL 117, 061301 (2016) [4] J. Lodewyck et al., Metrologia 53, 1123–1130 (2016) [5] R. Tyumenev et al., New J. Phys. 18 (2016) 113002 [6] C. Lisdat et al., Nat. Comm. 7, 12443 (2016) |
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Talk view |
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