Observation of the long-range potential well of the (6)1Σg+(3s+5s) state of Na2
Institut für Quantenoptik, Universität Hannover, Welfengarten
1, 30167 Hannover, Germany
2 Laboratoire Aimé Cotton, CNRS, Campus d'Orsay, Bâtiment 505, 91405 Orsay Cedex, France
Published online: 22 July 2003
We report on the first observation of the outer well of the state of Na2 molecule. The levels are populated in a molecular beam experiment with a three step laser excitation. The fact that these levels predissociate allows an almost background free detection by the appearance of atomic fluorescence. With this method almost all vibrational levels of the outer well are observed. The corresponding predissociation line widths show an oscillating behaviour. The theoretical description of the predissociation is presented in the framework of mapped Fourier grid Hamiltonian representation with optical potential, involving two coupled electronic states. Combining the spectroscopic information on energy positions and predissociation widths, a Rydberg-Klein-Rees potential curve is given for the outer well. Such a state could offer a reliable path for photoassociation of cold Na atoms and formation of ultracold Na2 molecules.
PACS: 33.80.Gj – Diffuse spectra; predissociation, photodissociation / 31.50.Gh – Surface crossings, non-adiabatic couplings / 42.62.Fi – Laser spectroscopy
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003