Hadron diffractive processes: the structure of soft pomeron and colour screening

On the basis of the experimental data on diffractive processes in pi p, pp and p (p) over bar collisions at intermediate, moderately high and high energies; we restore the scattering amplitude related to the t-channel exchange by vacuum quantum numbers by taking account of the diffractive s-channel rescatterings. At intermediate and moderately high energies, the t-channel exchange amplitude turns; with a good accuracy, into an effective pomeron which renders the results of the additive quark model. At superhigh energies the scattering amplitude provides a Froissart-type behaviour: with an asymptotic universality of cross sections such as sigma(pi p)(tot)/sigma(pp)(tot) --> 1 at s --> infinity. The quark structure of hadrons being taken into account at the level of constituent quarks, the cross sections of pion and proton (antiproton) in the impact parameter space of quarks, sigma(pi)(r(1 perpendicular to), r(2 perpendicular to); s) and sigma(p)(r(1 perpendicular to),r(2 perpendicular to), r(3 perpendicular to); s); are found as functions of s. These cross sections implicate the phenomenon of colour screening: they tend to zero at \r(i perpendicular to) - r(k perpendicular to)\ --> 0 The effective colour screening radius for pion (proton) is found for different s. The predictions for the diffractive cross sections at superhigh energies are presented.