The inclusive photon energy spectra
measured by the Large Hadron Collider forward (LHCf) experi
ment in the very forward region of LHC proton-proton collisions at are reported. The results fro
m the analysis of 0.30 nb
?1 of data collected in May 2010 in the two pseudorapidity regions of and are co
mpared with the predictions of the hadronic interaction
models DPMJET 3.04, EPOS 1.99, PYTHIA 8.145, QGSJET II-03 and SIBYLL 2.1, which are widely used in ultra-high energy cos
mic ray experi
ments. EPOS 1.99 and SIBYLL 2.1 show a reasonable agree
ment with the spectral shape of the experi
mental data, whereas they predict lower cross-sections than the data. The other
models, DPMJET 3.04, QGSJET II-03 and PYTHIA 8.145, are in good agree
ment with the data below 300 GeV but predict harder energy spectra than the data above 300 GeV.
The results of these comparisons exhibited features similar to those for the previously reported data for collisions.