Measurement of the proton-air inelastic cross section at root (s) approximate to 2 TeV from the EAS-TOP experiment

The proton-air inelastic cross section (σp-airinel) is measured at √s≈2  TeV at the EAS-TOP extensive air shower experiment by studying the absorption length of cosmic ray proton primaries cascades reaching the maximum development at the observation level. Primary energies, in the region E0=(1.5÷2.5)·10(15 ) eV, are selected through the EAS muon number (Nμ), and proton originated cascades at maximum development are selected by means of the shower size (Ne). The observed absorption length (λobs) is a convolution of the proton-air interaction length (λp-air) and of the shower and detector fluctuations. The conversion factor k=λobs/λint is obtained by means of simulations performed with the CORSIKA code and the QGSJET II and SIBYLL interaction models. The obtained value of the p-air inelastic cross section at √s≈2  TeV is σp-airinel=338±21(stat)±19(syst)-28(syst)  mb. The statistical and systematic uncertainties, as well as the relationships with the pp (p̅ p) total cross section measurements are discussed.