2018 Impact factor 4.843
Particles and Fields

Eur. Phys. J. C 10, 689-696
DOI 10.1007/s100529900160

Total $\gamma^*$p cross section

E. Gotsman - E. Levin - U. Maor - E. Naftali

School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Science, Tel Aviv University,
Tel Aviv, 69978, Israel

Received: 11 April 1999 / Published online: 28 September 1999

This paper shows that the approach based on Gribov's ideas for photon-proton interaction is able to describe the experimental data over a wide range of photon virtualities Q2 = 0-100GeV2 and energies $\sqrt{s} = W = 3\hbox{--}300\,\mathrm{GeV}$. A simple model is suggested which provides a quantitative way of describing the matching between short and long distances (between ``soft" and ``hard" processes) in photon-proton interaction at high energy. The main results of our analysis are: (i) the values of the separation parameters differentiating the soft and hard interactions are determined; (ii) the additive quark model can be used to calculate the soft contribution to the photon-proton interaction; (iii) a good description of the ratio $\sigma_{\mathrm{L}}/\sigma_{\mathrm{T}}$ is obtained; and (iv) a considerable contribution of the soft process at large Q2, and of hard processes at small Q2 was found.

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