Zeeman quantum beats in the polyatomic molecule propynal

Abstract

Zeeman quantum beats have been detected in the fluorescence emission of propynal (HC≡CCHO) in a molecular beam after excitation of single rovibronic levels in the first excited singlet state. The observed beat modulation amplitudes and frequencies of Zeeman sublevels as well as their decay rates are explained by spin-orbit interaction of individual hyperfine components with neighboring triplet hyperfine states.