Negative scattering length of ultracoldLi7gas

Abstract
We have improved the theoretical triplet ground-state potential of Li27 by means of an inverse perturbation analysis, and find that the diatomic scattering length for Li7 atoms in the F=2, mF=2 ground-state hyperfine level is negative. The consequences of this result for achieving Bose-Einstein condensation in a trapped ultracold Li7 gas sample are addressed