Yet another component on the order of α2(Zα)EF in the hyperfine splitting in muonium and hydrogen
Karshenboim S. G. , Shelyuto V. A. , Eides M. I.
A component of the hyperfine splitting on the order of a2{Za)EF induced by a polarization insertion into a "radiation" photon is calculated. This component turnsouttobe ( 0.310742...) [a2(Za)/ir]EF or, numerically, 0,l7kHzfor muonium and — 0.054 kHz for hydrogen.