NEW EXPERIMENTAL LIMITS TO THE TIME VARIATIONS OF G(P)(M(E) M(P)) AND ALPHA

A new experimental limit to the possible time variation of the proton gyromagnetic ratio times the electron-to-proton mass ratio has been obtained from the frequency comparison data between Cs and Mg atomic beam standards. The measurements, made over a period of one year, lead to an upper limit for the rate of change of g(p)(m(e)/m(p)) of 5.4 x 10(-13)/yr. This result, based only on the validity of the quantum mechanical theory of the atomic spectra, together with astrophysical data regarding analogous products of atomic fundamental constants, leads also to a new limit for the time stability of the fine structure constant a (2.7 x 10(-13)/yr).