Constancy of the fundamental constants
Domnin Yu. S., Malimon A. N., Tatarenkov V. M., Shchumyatskii P. S.
A time variation of the ratio of the frequencies of quantum standards for the optical and rf ranges has been observed experimentally. With respect to the frequency of the standard transition of the Cs atom, the frequencies of He-Ne/CH4 lasers stabilized on the basis of the F\ and Ε components of methane decreased by 4.7 ± 0.7 and 4.3 + 1.7 kHz, respectively, over an interval of 4 years, 8 months. The hypothesis of a time variation of the fundamental constants is discussed as a possible reason.