Shape fluctuations and optical transition of He${}_2^{\ast }$ excimer tracers in superfluid ${}^4$He

Wei Guo, Andrei I. Golov

Metastable He${}_2^{\ast }$ excimer molecules have been utilized as tracer particles of the normal component in superfluid ${}^4$He (He II) which can be imaged via laser-induced fluoresc…