  We study the spectral properties of the one-dimensional Kondo lattice model
as function of the exchange coupling, the band filling, and the quasimomentum
in the ferromagnetic and paramagnetic phase. Using the density-matrix
renormalization group method, we compute the dispersion relation of the
quasiparticles, their lifetimes, and the Z-factor. As a main result, we provide
evidence for the existence of the spinpolaron at partial band fillings. We find
that the quasiparticle lifetime differs by orders of magnitude between the
ferromagnetic and paramagnetic phase and depends strongly on the quasimomentum.
