Hadron diffractive scattering at ultrahigh energies, real part of the amplitude and Coulomb interaction

Abstract

On the basis of requirements of unitarity and analyticity we analyze the real and imaginary parts of the $pp^\pm$ scattering amplitudes at recent ultrahigh energies, 1-100 TeV. The predictions for the region $\sqrt s > 100$ TeV and ${\bf q}^2<0.4$ GeV$^2$ are given supposing the black disk asymptotic regime. It turns out that the real part of the amplitude is concentrated in the impact parameter space at the border of the black disk. The interplay of hadron and Coulomb interactions is discussed in terms of the $K$-matrix function. The $pp$ diffractive scattering cross section at 7 TeV is calculated with Coulomb interaction taken into account.