SPIN DYNAMICS IN SPIN-POLARIZED FERMI SYSTEMS

We present a simple description. of transverse dynamics of dilute Ferm i systems in terms of statistical quasiparticles. We give explicit exp ressions for the quasiparticle interaction function and collision inte gral at arbitrary temperatures, and discuss the implications of this a pproach in classical and degenerate regions, including the quantum gas es. The results provide an unexpected explanation for the zero-tempera ture attenuation in transverse spin dynamics and peculiar I-2-terms in molecular field as imaginary (pole) and real (principal) parts of the quasiparticle interaction function.