SYMPATHETIC COOLING OF LI-6 ATOMS

We use recently measured cold photoassociation and two-photon data to extract the singlet and triplet accumulated radial phases of interacti ng ground-state lithium atoms. Using the resulting values we predict s cattering lengths, Feshbach resonances, and exchange decay rates for c old collisions between Li-7 and Li-6 atoms that are of interest for th e possibility of sympathetic cooling of Li-6 and for the coexistence o f the bosonic and fermionic quantum-degenerate phases of Li-7 and Li-6 . In addition, we calculate scattering lengths and exchange decay rate s for cold collisions between identical lithium isotopes in different hyperfine states. These quantities are used to examine the possibiliti es of coexisting Li-7 Bose condensates and of evaporatively cooling co existing Li-6 subsystems.