  The determination of the primary energy and mass of ultra-high-energy
cosmic-rays (UHECR) generating extensive air-showers in the Earth's atmosphere,
relies on the detailed modeling of hadronic multiparticle production at
center-of-mass (c.m.) collision energies up to two orders of magnitude higher
than those studied at particle colliders. The first Large Hadron Collider (LHC)
data have extended by more than a factor of three the c.m. energies in which we
have direct proton-proton measurements available to compare to hadronic models.
In this work we compare LHC results on inclusive particle production at
energies sqrt(s) = 0.9, 2.36, and 7 TeV to predictions of various hadronic
Monte Carlo (MC) models used commonly in cosmic-ray (CR) physics (QGSJET, EPOS
and SIBYLL). As a benchmark with a standard collider physics model we also show
PYTHIA (and PHOJET) predictions with various parameter settings. While
reasonable overall agreement is found for some of the MC, none of them
reproduces consistently the sqrt(s) evolution of all the observables. We
discuss implications of the new LHC data for the description of cosmic-ray
interactions at the highest energies.
