Resonant Control of Elastic Collisions between (NaK)-Na-23-K-40 Molecules and K-40 Atoms

We have demonstrated the resonant control of the elastic scattering cross sections in the vicinity of Feshbach resonances between (NaK)-Na-23-K-40 molecules and K-40 atoms by studying the thermalization between them. The elastic scattering cross sections vary by more than 2 orders of magnitude close to the resonance, and can be well described by an asymmetric Fano profile. The parameters that characterize the magnetically tunable s -wave scattering length are determined from the elastic scattering cross sections. The observation of resonantly controlled elastic scattering cross sections opens up the possibility to study strongly interacting atom-molecule mixtures and improve our understanding of the complex atom-molecule Feshbach resonances.