Measurement of the hyperfine coupling constants and absolute energies of the 8p 2P1/2 and 8p 2P3/2 levels in atomic cesium

We report measurements of the hyperfine coupling constant for the 8p 2P1/2 level of atomic cesium, 133Cs, with a relative uncertainty of & AP;0.019%. Our result is A = 42.933 (8) MHz, in good agreement with recent theoretical results. We also examine the hyperfine structure of the 8p 2P3/2 level, and derive new values for the energies of the 8p 2P1/2 and 8p 2P3/2 levels of cesium.