Asymptotic behavior of the total cross section ofp−pscattering and the Akeno cosmic ray data

I present a new determination of the total cross section for proton-proton collisions from the recent Akeno results on the absorption of cosmic ray protons in $p$-air collisions. An extrapolation to SSC energies suggests ${\sigma }_{\mathrm{tot}}\mathrm{}(p-p)\mathrm{}\approx 160-170$ mb. I also comment on a possible sensitivity of the $p$-air cross section determinations to assumptions on the inelasticity of nuclear collisions at high energy.