Hyperfine Interaction, Zeeman and Stark Effects for Excited States in Potassium

Using the optical double resonance and level crossing methods, properties of several excitedS,P, andDstates in39K were studied. TheSandDstates were populated using stepwise excitation with the firstPstate as an intermediate level. An rf lamp and a CW dye laser were used in the first and second excitation steps, respectively. The studiedPstates were populated in the cascade decay of states, excited with the laser. The following results for the magnetic depole interaction constant a, the LandégJfactor, and the tensor polarizability α2were obtained for the studied states: 72S1/2: a = 10.78(5) MHz,gJ= 2.0020(10); 82S1/2: a = 5.99(8) MHz,gJ= 2.0028(12); 62P1/2: a = 4.05(7) MHz,gJ= 0.6663(4); 62P3/2: a = 0.89(5) MHz,gJ= 1.3337(8); 72P1/2: a = 2.18(5) MHz,gJ= 0.6659(6); 72P3/2: a = 0.49(4) MHz,gJ= 1.3336(8); 52D3/2: |a| = 0.44(10) MHz,gJ= 0.7997(7), |α2| = 9.64(45) MHz/(kV)/cm)2; 52D5/2: |a| = 0.24(7) MHz,gJ= 1.2004(10), |α2| = 13.4(7) MHz/(kV)/cm)2; 62D3/2: |a| = 0.2(2) MHz,gJ= 0.7997(14), |α2| = 33.8(1.7) MHz/(kV)/cm)2; 62D5/2: |a| = 0.1(1) MHz,gJ= 1.2013(20), |α2| = 47.6(2.4) MHz/(kV)/cm)2. Theoretical values for the magnetic dipole interaction constant have been obtained using a limited many-body perturbation expansion. The Polarization effect, which is due to single excitations from the restricted Hartree-Fock model, is included to all orders, while the true correlation effect is omitted. The results are compared with the experimental values, and the agreement is found to be quite good. For theSandPstates the polarization effect is of the order of 10-20%, and it is responsible for roughly half of the deviation of the Hartree-Fock values from experiment. For theDstates, on the other hand, the effects are much more drastic. The sign of theafactors has not been measured. The perturbative calculation yields positive values for all2D3/2states and negative values for all2D5/2 states. The theoretical magnitudes are in agreement with the observed ones.