Redetermination of the Hyperfine Splittings of Hydrogen and Deuterium in the Ground State

Abstract

The hyperfine splittings of hydrogen and deuterium in the $1^{2}S_{\frac{1}{2}}$ state have been remeasured by the atomic beam method. It is found that $\ensuremath{\Delta}\ensuremath{\nu}(\mathrm{H})=(1420.40573\ifmmode\pm\else\textpm\fi{}0.00005)\ifmmode\times\else\texttimes\fi{}{10}^{6} invsec,$ $\ensuremath{\Delta}\ensuremath{\nu}(\mathrm{D})=(327.384302\ifmmode\pm\else\textpm\fi{}0.000030)\ifmmode\times\else\texttimes\fi{}{10}^{6} invsec.$ The result for hydrogen is in agreement with a recent measurement of Wittke and Dicke. It is significant disagreement with an earlier atomic beam measurement.