  The statistical scattering properties of wave transport in disordered
waveguides are derived perturbatively within the transition matrix formalism.
The limiting macroscopic statistic of the wave transport, emerges as a
consequence of a generalized central-limit-theorem: the expectation values of
macroscopic observables depend only on the first and second moments of the
reflection matrix of individual scatterers. This theoretical approach does not
consider any statistical assumption on the scattering properties of the
individual scatterers and it is fully consistent with the optical theorem. The
results are found in the so called dense-weak-scattering limit and in the
ballistic regime.
