The fractional shift in the electronic gyromagnetic ratio in muonium is calculated as -7.8±2.3 ppm under Kr pressure of 230 psi at 30°C. Together with the experimental data of The University of Chicago Group, we obtain the values $\frac{{\mu }_e}{{\mu }_{\mu }}=206.766\mathrm{}70\left(93\right)\mathrm{}$ for the electron to muon magnetic moment ratio, $\frac{{\mu }_{\mu }}{{\mu }_p}=3.183\mathrm{}349\mathrm{}\left(15\right)\mathrm{}$ for the muon to proton magnetic moment ratio, $\frac{m_{\mu }}{m_e}=206.767\mathrm{}96\left(95\right)\mathrm{}$ for the muon to electron mass ratio, and ${\alpha }^{-1\mathrm{}}=137.036\mathrm{}46\left(36\right)\mathrm{}$ for the inverse fine-structure constant.

• Received 4 November 1971

DOI:https://doi.org/10.1103/PhysRevLett.28.199