Photoassociation spectroscopy of Rb287 (5 s12 +5 p12) 0g- long-range molecular states: Analysis by Lu-Fano graph and improved LeRoy-Bernstein formula

We report on cold atom photoassociation of Rb87 giving spectroscopy data of the (5 s12 +5 p12) 0g- long-range molecular states in the asymptotic range of [-12.5 cm-1, -1.5 cm-1] below the dissociation limit. Using a Lu-Fano approach to analyze the data, we show that an improved LeRoy-Bernstein model has to be applied. This approach lets us determine the phase shift of the wave function at the dissociation limit of the 0g- series. © 2006 The American Physical Society.