Feshbach resonances and weakly bound molecular states of boson-boson and boson-fermion NaK pairs

We conduct a theoretical study of magnetically induced Feshbach resonances and near-threshold bound states in isotopic NaK pairs. Our calculations accurately reproduce Feshbach spectroscopy data on Na-40 K and explain the origin of the observed multiplets in the p wave [Phys. Rev. A 85, 051602(R) (2012)]. We apply the model to predict scattering and bound state threshold properties of the boson-boson Na-39 K and Na-41 K systems. We find that the Na-39 K isotopic pair presents broad magnetic Feshbach resonances and favorable ground-state features for producing nonreactive polar molecules by two-photon association. Broad s-wave resonances are also predicted for Na-41 K collisions.