Measurement of the Hyperfine Structure of 2P122 State in Hydrogen

The separated-oscillatory-field technique of subnatural-linewidth rf spectroscopy has been used to completely resolve the hyperfine structure of the 2P122 state of hydrogen. The three-component 2S122-2P122 resonance observed in zero magnetic field was fitted by a superposition of numerically obtained line profiles to determine the hyperfine spliting of the 2P122 state. The result is 59.22(14) MHz.