Abstract
Zeeman splittings of the 2P3/2 excited state of caesium atom are analyzed theoretically. The magnetic sub-levels constitute four groups for strong magnetic fields (Hz > 249 × 10-4 T) in which the magnetic quantum numbers of the split levels arrange themselves with regularity. For intermediate magnetic fields (249 × 10-4 T > Hz > 61 × 10-4 T), there occur crossings between sublevels with different hyperfine quantum numbers F. It is also revealed that the magnetic sublevels in F = 3 cross each other in a complex manner for weak magnetic fields (41 × 10-4 T > Hz > 0.08 × 10-4 T). Finally, we obtain all the values of the magnetic fields and the energy levels which determine the level crossings.