On the universality of cross sections of hadron-hadron(nuclei) collisions at superhigh energies

We analyze the pattern of the onset of complete absorption (the black limit) in the high energy hadron-hadron collisions. The black limit arises due to the hard and soft interaction dynamics as a function of the impact parameters b. Both hard and soft mechanisms provide universal dependence of the partial amplitude of the high energy elastic hadron- hadron scattering on the impact parameter ${\bf b}$ and result in the radius of interaction proportional to $\ln (s/s_0)$. We find that with increase of the collision energies hard interactions lead to a faster increase of the impact parameter range where the partial wave amplitudes are approaching the unitarity limit. Consequently, we argue that at super high energies whenthe radius of hadronic interactions significantly exceeds static radii of the interacting hadrons(nuclei) the ratio of total cross sections of nucleon-nucleon, meson-nucleon, hadron-nucleus, nucleus-nucleus collisions becomes equal to one. The same universality is also expected for the structure functions of nuclei: $F_{2 A}(x,Q^2)/F_{2 N}(x,Q^2)> \to 1$, at very small $x$, and for the ratio $>\sigma_{gamma A}/>\sigma_{>\gamma p}\to 1$ at superhigh energies. We analyze how accounting for the energy dependence of the interaction radii changes the geometry of hadron-nucleus and nucleus-nucleus collisions, the energy dependence of total, absorption and inelastic cross sections, the distribution over the number of wounded nucleons in proton-nucleus collisions and find that these effects are noticeable already for the LHC energies and even more so close to the Greisen-Zatsepin-Kuzmin limit.Comment: 24 pages, 9 figure

Effect of pp-cut contribution on the diffraction cone slope

The author considers the effect of the cut contribution including enhanced ones on the diffraction cone slope: b(E, t)=1/tln ((d sigma /dt)/(d sigma /dt)/sub t=0/) approximately=b/sub 0/(E)+tb/sub 0/'(E) in the region of small mod t mod <or approximately=1/ alpha /sub P/'ln E and of very high energies E=E/sub lab/. The question is of great interest in connection with the CERN data on b(E, t) for pp-scattering at E approximately 10/sup 3/ GeV. (7 refs)

On the total cross sections and diffraction cone slope

The authors compare the theoretical total cross-sections of pp scattering with the experimental ones got by analyzing the data obtained at CERN and Serpukhov from 10 GeV upwards

Total cross sections and cone slope-theory and experiment

The previously presented (1969-1970) description of all the known experimental data on pi N, KN, and NN-NN interactions has shown that there exists a single system of parameters that give good agreement with experiment (without enhanced diagrams). The present article compares the theory, given the same parameters, with the new data of the Institute of High Energy Physics (IHEP) and CERN on the values sigma /sup tot/ and on the slopes b/sub 0/=b/sub 0/(E) of the pp- scattering cone. (10 refs)