  In this paper, our goal is to make a simultaneous analysis of the high- and
low-P_T parts of the charged-hadron P_T spectrum measured by the ALICE
collaboration in central Pb-Pb collisions at sqrt{s}=2.76 TeV at the Large
Hadron Collider (LHC), based on models which have been successfully applied and
constrained in Au-Au collisions at Relativistic Heavy Ion Collider (RHIC). For
the hydrodynamical modeling with which we obtain the low-P_T spectrum, we have
computed the initial conditions based on perturbative QCD (pQCD) minijet
production and saturation. The sensitivity of the obtained charged-hadron P_T
spectrum on the hydrodynamic model parameters is studied. For the high-P_T
part, we apply a number of parton-medium interaction models, which are tuned to
describe the nuclear suppression factor R_AA measured at the RHIC in central
Au-Au collisions at sqrt{s}=200 GeV. We find that the higher kinematic reach of
the LHC, manifest in the hardening of the pQCD parton spectral slope, is in
principle very efficient in discriminating the various models. However, due to
the uncertainties in the p-p baseline, none of the tested models can be firmly
ruled out with the present ALICE data. Comparison with the LHC data in this
approach also shows that the matching of the hydrodynamic and pQCD+jet
quenching components leaves fairly little room for other hadron production
mechanisms in the cross-over region P_T=4-5 GeV.
