Study of the Born-Oppenheimer Approximation for Mass-Scaling of Cold Collision Properties

Abstract

Asymptotic levels of the A ${}^1{\Sigma }_u^{+}$ state of the two isotopomers ${}^{39}{\mathrm{K}}_2$ and ${}^{39}{\mathrm{K}}^{41}\mathrm{K}$ up to the dissociation limit are investigated with a Doppler-free high resolution laser-spectroscopic experiment in a molecular beam. The observed level structure can be reproduced correctly only if a mass dependent correction term is introduced for the interaction potential. The applied relative correction in the depth of the potential is $10^{-6}$, which is in the order of magnitude expected for corrections of the Born-Oppenheimer approximation. A similar change in ground state potentials might lead to significant changes of mass-scaled properties describing cold collisions like the s-wave scattering length.

8 pages, 6 figures

Cited by in corpus (1)

• Collisional and molecular spectroscopy in an ultracold Bose-Bose mixture