  We present femtosecond transient transmission (or absorbance) measurements in
silicon nanowires in the energy range 1.1-3.5 eV, from below the indirect
band-gap to above the direct band-gap. Our pump-probe measurements allow us to
give a complete picture of the carrier dynamics in silicon. In this way we
perform an experimental study with a spectral completeness that lacks in the
whole literature on carrier dynamics in silicon. A particular emphasis is given
to the dynamics of the transient absorbance at the energies relative to the
direct band gap at 3.3 eV. Indeed, the use of pump energies below and above 3.3
eV allowed us to disentangle the dynamics of electrons and holes in their
respective bands. The band gap renormalization of the direct band gap is also
investigated for different pump energies. A critical discussion is given on the
results below 3.3 eV where phonon-assisted processes are required in the
optical transitions.
