Precision Spectroscopy of Atomic Hydrogen and Variations of Fundamental Constants

International audienceIn 2003 we have measured the absolute frequency of the (1S, F=1, mF=± 1) (2S, F=1, mF=± 1) two-photon transition in atomic hydrogen. By comparison with the earlier measurement in 1999 we can set an upper limit on its variation of ( 29± 57) Hz within 44 months. We have combined this result with recently published results of optical transition frequency measurements in the 199Hg ion and comparison between clocks based on 87Rb and 133Cs. From this combination we deduce the limits for fractional time variations of the fine structure constant yr 1 and for the ratio of 87Rb and 133Cs nuclear magnetic moments yr 1. This is the first precise restriction for the fractional time variation of made without assumptions about the relative drifts of the constants of electromagnetic, strong and weak interactions