Knowledge Bank

The opto-thermal detection method has been used in conjuction with an F-center laser to obtain rotationally resolved infrared spectra of the water dimer under jet cooled conditions. The most intense sub-band observed to date is $Ka0\leftarrow 1$ which shows three strong 0 branches associated with different tunneling states. Assignment and fitting of these spectra is underway. The observed transitions are broader than the instrumental linewidth due to vibrational predissociation. Transitions associated with the different tunneling states are found to have different linewidths, indicating that vibrational symmetry may play an important role in determining the rate of dissociation.