Determination of collisional properties of cold Na atoms from analysis of bound-state photoassociation and Feshbach resonance field data

We review the information on the interactions between cold ground-state Na atoms following from ${\mathrm{Na}}_2$ bound states, a Na photoassociation experiment, and a recent observation of field-induced Feshbach resonances in a Na Bose condensate. We obtain a set of Na interaction parameters that is in excellent agreement with all these experimental data. The existing discrepancy between different values for the scattering length $a_{1,-1}$ of Na atoms in the $|1,-1〉$ hyperfine state is resolved. The present interaction parameters enable us to give accurate predictions for the singlet and triplet scattering lengths $a_S$ and $a_T,$ $a_{1,-1},$ scattering lengths for collisions between Na atoms in other hyperfine states, and resonance fields of several yet unobserved Feshbach resonances. We find $a_S=(19.1\mathrm{}\pm {2.1)a}_0,a_T=(65.3\mathrm{}\pm {0.9)a}_0,$ and $a_{1,-1}\mathrm{}(B=0\mathrm{})=(55.4\mathrm{}\pm {1.2)a}_0.$