2018 Impact factor 2.481
Hadrons and Nuclei
Eur. Phys. J. A 5, 209-228

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

L.G. Dakhno - V.A. Nikonov

St.Petersburg Nuclear Physics Institute, Gatchina, 188350 St.Petersburg, Russia (e-mail: dakhno@hep486.pnpi.spb.ru;
nikon@rec03.pnpi.spb.ru)

Received: 15 December 1998 Communicated by V.V. Anisovich

Abstract
On the basis of the experimental data on diffractive processes in $\pi p$, pp and $p \bar p$ 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 $\sigma^{tot}_{\pi p}/\sigma^{tot}_{pp} \to 1$ at $s \to \infty$. 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, $\sigma_{\pi}(\vec {r}_{1\perp},\vec {r}_{2\perp};s)$and $\sigma_p(\vec {r}_{1\perp},\vec {r}_{2\perp},\vec
{r}_{3\perp};s)$, are found as functions of s. These cross sections implicate the phenomenon of colour screening: they tend to zero at $\vert\vec r_{i\perp}-\vec r_{k\perp}\vert \to 0$.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.

PACS
14.20.Dh Protons and neutrons - 14.40.Aq $\pi$, K and $\eta$ mesons - 13.85.Dz Elastic scattering - 13.85.Lg Total cross sections


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