Parametrization of hadronic cross sections in the range 10-2-102 TeV

Present estimations of proton-proton total cross sections at very high energies are obtained from cosmic rays (>1017 eV): by means of some approximations, it is possible to get a value for the proton-proton total cross section from the knowledge of the proton-air cross section at these energies. Besides, total cross sections are measured with present day high energy colliders up to nearly 2 TeV in the center of mass (∼1015 eV in the lab.): several theoretical, empirical or semi-empirical parametrizations, very successful for interpolation at accelerator energies, can then be used to extrapolate the measured value to cosmic ray energies and get a reasonable estimation of cross sections at higher energies (∼1017 eV). Here we use a phenomenological model based on the Multiple-Diffraction approach to estimate proton-proton total cross sections at cosmic ray energies: on the basis of a forecasting regression analysis we determine confident error bands. We show that our predictions are highly sensitive to the employed data for extrapolation. When both cross section estimations--from accelerators data and most cosmic rays results--are compared, a disagreement is observed, amounting to more than 10%, showing a discrepancy beyond statistical errors