Meson corrections to the hyperfine structure in hydrogen

The authors have previously shown that the form factor of the proton, measured by Hofstadter, implies an energy shift in the hyperfine structure of atomic hydrogen. Uncertainties in this method of applying the Hofstadter data, due to the effects of virtual mesons, are investigated in an approximate way and found to be small, on the order of one to two percent of the total correction. Under certain assumptions about the form of the amplitudes for various photoproduction processes, we conclude that the value of the fine-structure constant implied by the hyperfine structure (hfs) measurement of Kusch disagrees with the value obtained from the Lamb shift by 34±21 ppm.