Precise measurement of electronic gJ value of helium,gJ(4He,23S1)

We report the measurement of $\text{g}{}_{\mathrm{J}}\text{(}{}^4\text{He,2}{}^3\text{S}{}_1\text{)}\text{g}{}_{\mathrm{J}}\text{(}{}^{85}\text{Rb}\text{,5}{}^2\text{S}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{)}$ by the atomic beam magnetic reson ance method using separated oscillating fields, and hence the determination $\text{g}{}_{\mathrm{J}}\text{(}{}^4\text{He,2}{}^3\text{S}{}_1\text{)}\text{g}{}_{\mathrm{J}}\text{(H,1}{}^2\text{S}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{)}\text{? 1? (23.19±0.07) × 10}{}^{\mathrm{?6}}$, which agrees with theory and with other less precise recent measurements.