  We suggest to use net-baryon rapidity distributions in central relativistic
heavy-ion collisions at SPS, RHIC and LHC energies in order to probe saturation
physics. Within the color glass condensate framework based on small-coupling
QCD, net-baryon rapidity distributions are shown to exhibit geometric scaling.
In a comparison with RHIC data in Au + Au collisions at sqrt(s_NN) = 62.4 GeV
and 200 GeV the gradual approach to the gluon saturation regime is
investigated. Predictions for net-baryon rapidity spectra and the mean rapidity
loss in central Pb + Pb collisions at LHC energies of sqrt (s_NN) = 5.5 TeV are
made.
