We demonstrated that final states of ultracold scattering between atom and
molecule can be selectively produced using dynamic magnetic fields of multiple
frequencies. The mechanism of the dynamic magnetic field control is based on a
generalized quantum Zeno effect for the selected scattering channels. In
particular, we use an atom-molecule spin flip scattering to show that the
transition to the selected final spin projection of the molecule in the
inelastic scattering can be suppressed by dynamic modulation of coupling
between the Floquet engineered initial and final states