Production spectra of zero-degree neutral particles measured by the LHCf experiment

The LHC-forward (LHCf) experiment, situated at the LHC accelerator, has measured neutral particles production in a very forward region (pseudo-rapidity $\eta > 8.4$) in proton-proton and proton-lead collisions. The main purpose of the LHCf experiment is to test hadronic interaction models used in ground based cosmic rays experiments to simulate cosmic rays induced air-showers in the Earth's atmosphere. The experiment is composed of two independent detectors located at 140m from the ATLAS interaction point (IP1) on opposite sides; each detector is composed of two sampling and position sensitive calorimeters. In this paper, latest published physics results from p-p and p-Pb collisions (at $\sqrt{s} = 7, 2.76$ TeV and $\sqrt{s_{NN}} = 5.02$ TeV, respectively) compared with Monte Carlo predictions of DPMJET, EPOS, PYTHIA, QGSJET and SIBYLL event generators will be presented. In particular, the inclusive energy spectra of neutrons in p-p collisions and the transverse and longitudinal momentum spectra of neutral pions for different pseudo-rapidity ranges in p-p and p-Pb collisions will be shown; then, test of Feynman scaling hypothesis using neutral pion spectra will be discussed. Preliminary results of photon inclusive energy spectra in p-p collisions at $\sqrt{s} = 13$ TeV will be also presented.