  Employing dynamical cluster quantum Monte Carlo calculations we show that the
single particle spectral weight A(k,w) of the one-band two-dimensional Hubbard
model displays a high energy kink in the quasiparticle dispersion followed by a
steep dispersion of a broad peak similar to recent ARPES results reported for
the cuprates. Based on the agreement between the Monte Carlo results and a
simple calculation which couples the quasiparticle to spin fluctuations, we
conclude that the kink and the broad spectral feature in the Hubbard model
spectra is due to scattering with damped high energy spin fluctuations.
