Microwave Resonance in Nitric Oxide: Lambda Doubling and Hyperfine Structure

Abstract

The microwave spectrum arising from transitions between Zeeman levels in the $^{2}\ensuremath{\Pi}_{\frac{3}{2}}$, $J=\frac{3}{2}$ state of nitric oxide is reinvestigated with particular regard to the lambda doubling which is observable for electric-dipole transitions. This doubling is compared with the theory of Karnaugh. The experiments also give a new and improved determination of the nuclear hyperfine coupling constants and of the molecular splittings. The theory of the hyperfine effect is reexamined in detail.