English

Hadron collisions at ultrahigh energies: black disk or resonant disk modes?

High Energy Physics - Phenomenology 2015-06-22 v3

Abstract

The analysis of current ultrahigh energy data for hadronic total cross sections and diffractive scattering cross sections points to a steady growth of the optical density with energy for elastic scattering amplitudes in the impact parameter space, bb. At LHC energy the profile function of the pppp-scattering amplitude, T(b)T(b), reaches the black disk limit at small bb. Two scenarios are possible at larger energies, s\ga100\sqrt{s}\ga 100 TeV. First, the profile function gets frozen in the black disk limit, T(b)1T(b)\simeq 1 while the radius of the black disk Rblack  diskR_{black\;disk} is increasing with s\sqrt s, providing σtotln2s\sigma_{tot}\sim \ln^2s, σelln2s\sigma_{el}\sim \ln^2s, σinelln2s\sigma_{inel}\sim \ln^2s. In another scenario the profile function continues to grow at s\ga100\sqrt{s}\ga 100 TeV approaching the maximal value, T(b)2T(b)\simeq 2, that means the resonant disk mode. We discuss features of the resonant disk mode when the disk radius, Rresonant  diskR_{resonant\;disk}\,, increases providing the growth of the total and elastic cross sections σtotln2s\sigma_{tot}\sim \ln^2s, σelln2s\sigma_{el}\sim \ln^2s, but a more slow increase of inelastic cross section, σinellns\sigma_{inel}\sim \ln s.

Keywords

Cite

@article{arxiv.1408.0692,
  title  = {Hadron collisions at ultrahigh energies: black disk or resonant disk modes?},
  author = {V. V. Anisovich and V. A. Nikonov and J. Nyiri},
  journal= {arXiv preprint arXiv:1408.0692},
  year   = {2015}
}

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9 pages