Using a simple model of long-range impurity scattering, we illustrate
how different transport and Hall relaxation rates may arise when the e
lectron quasiparticle picture breaks down. We show how a broad and inc
oherent spectral function requires the use of a quantum version of the
Boltzmann equation. This leads to unusual transport properties, in pa
rticular, a Hall relaxation rate which is independent of the quasipart
icle scattering rate.