Redetermination of the hyperfine structure of the 6p 2 P 3/2 level in Cs133 by the zero field optical double resonance method

By combining recent level crossing data with the results from a modified atomic beam experiment by Buck, Rabi, and Senitzky in 1956, a Landég _j factor deviating about 0.6% from the LS-value ?1.3341 is obtained for the 6p ² P _3/2 level of Cs¹³³. As this large deviation is difficult to explain, a remeasurement of the hyperfine structure of this level was performed by the zero field optical double resonance method. For the magnetic dipole and the electric quadrupole interaction constantsa andb we obtain $$a(6p{}^2P_{{3 \mathord{\left/ {\vphantom {3 2}} \right. \kern-\nulldelimiterspace} 2}} ) = 50.31(5)MHz,b(6p{}^2P_{{3 \mathord{\left/ {\vphantom {3 2}} \right. \kern-\nulldelimiterspace} 2}} ) = - 0.30(33)MHz.$$ With these new values ag _j factor of ?1.3341 (15) is deduced for the 6p ² P _3/2 level of Cs¹³³, in agreement with the LS-value.