  We present a perturbative QCD based model for vacuum and in-medium
hadronization. The effects of induced energy loss and nuclear absorption have
been included. The main objective is the determination of the relative
contribution of these mechanisms to the multiplicity ratio observable, measured
in semi-inclusive deep-inelastic scattering off deuterium and nuclear targets.
This is directly related to the determination of the production length, $Lp$,
necessary for a quark to turn into a prehadron. We compare our results with
HERMES data for multiplicity ratio and $p_t$-broadening, and show that the
description of the whole data set, keeping the model parameters fixed, puts
strong constrains on $Lp$. Contrary to induced-energy-loss based models, we
find an important contribution from nuclear absorption at HERMES energies.
Finally, we discuss some consequences of our study for the LHC physics, and we
present the model predictions for the future EIC experiment.
