Anticrossing spectroscopy of K Rydberg atoms using 300-K blackbody radiation

Abstract
The avoided crossings in an electric field of K s and p states with the nearly hydrogenic Stark manifold states have been investigated using 300-K blackbody radiation. Anticrossings between states of the same ‖mj‖ for which the ‖ml‖ values are the same or differ by one are encountered. The anticrossings between states of the same ‖ml‖ are quite wide as they are due to core penetration and polarization effects. The anticrossings for which ‖ml‖ differs by one are produced by the spin-orbit interaction and are accordingly quite small. We present results for the ns states for n in the range 1829 and for the np states for n in the range 1923.