ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
A reduced description for spectral line shapes in isolated ultracold polyatomic molecules is developed. The vibrational degrees of freedom are partitioned into a system and a bath. The system modes are treated using a Green function eigenstate-free procedure. The bath modes induce intramolecular vibrational redistribution (IVR) and in addition are responsible for intramolecular dephasing resulting from their thermal fluctuations. The effects of the bath are introduced statistically via correlation functions. Application is made to the dispersed fluorescence of ultracold anthracene in a supersonic beam, which shows progression of narrow lines (Raman) and broad redistributed fluorescence. The observed red shift (with respect to the absorption) and line broadening in the emission indicate that the frequencies of the bath modes are on the average 6.4% lower in the electronically excited state compared with the ground state. We further obtain the IVR rates in the high energy region.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.453177
