  Despite the paradigmatic nature of the Fermi-polaron model, the theoretical
description of its nonlinear dynamics poses challenges. Here, we apply a
quantum kinetic theory of driven polarons to recent experiments with ultracold
atoms, where Rabi oscillations between a Fermi-polaron state and a
non-interacting level were reported. The resulting equations separate
decoherence from momentum relaxation, with the corresponding rates showing a
different dependence on microscopic scattering processes and quasi-particle
properties. We describe both the polaron ground state and the excited
repulsive-polaron state and we find a good quantitative agreement between our
predictions and the available experimental data without any fitting parameter.
Our approach not only takes into account collisional phenomena, but also it can
be used to study the different roles played by decoherence and the collisional
integral in the strongly interacting highly-imbalanced mixture of Fermi gases.
