Feshbach resonances in $^{23}\mathrm{Na}+$$^{39}\mathrm{K}$ mixtures and refined molecular potentials for the NaK molecule

We present a detailed study of interspecies Feshbach resonances of the bosonic $^{23}\mathrm{Na}+$$^{39}\mathrm{K}\( mixture for magnetic fields up to \)750 \, \mathrm{G}\( in various collision channels. A total of fourteen Feshbach resonances are reported, as well as four zero crossings of the scattering length and three inelastic two-body loss features. We use the observed magnetic field locations of the resonant features together with the known data on \)^{23}\mathrm{Na}+$$^{40}\mathrm{K}\( to refine the singlet and triplet ground state potentials of NaK and achieve a consistent description of Feshbach resonances for both, the Bose-Bose mixture of \)^{23}\mathrm{Na}+$$^{39}\mathrm{K}\( as well as the Bose-Fermi mixture of \)^{23}\mathrm{Na}+$$^{40}\mathrm{K}$.