English

"Soft" Hadronic Cross Sections Challenge Hidden Dimensions

High Energy Physics - Phenomenology 2015-03-19 v1 High Energy Physics - Theory

Abstract

High energy measurements of the inelastic proton-proton cross sections, at the LHC at s\sqrt s=7 TeV and by Auger at 57 TeV, have validated previous evidence from data collected over a wide range of energies that the total and inelastic cross sections for pppp and pˉp\bar pp interactions saturate the Froissart bound of ln2s\ln^2 s. Although the data themselves did not cover truly asymptotic energies, our recent analysis of these data obtained the asymptotic ratio \sigin/\sigtot=0.509±0.021\sigin/\sigtot=0.509\pm 0.021, consistent with the value of 1/2 required for scattering by a black disk; further, the forward scattering amplitude became purely imaginary for ss\rightarrow \infty, confirming the black disk interpretation. In addition, the limiting black disk behavior has been independently confirmed by an analysis of Schegelsky and Ryskin including LHC data on the shrinkage of the slope of the forward elastic scattering cross section. Unless one considers these results, emerging from an analytic amplitude analysis of data over an energy range of 6s570006\le \sqrt s\le 57000 GeV, a complete numerical accident, we rule out any new physics thresholds that contribute higher powers of lns\ln s or, worse, powers of ss to the energy dependence of cross sections {\it at any energy}. This includes theories with additional dimensions of space-time, whose existence is challenged.

Keywords

Cite

@article{arxiv.1201.0960,
  title  = {"Soft" Hadronic Cross Sections Challenge Hidden Dimensions},
  author = {Martin M. Block and Francis Halzen},
  journal= {arXiv preprint arXiv:1201.0960},
  year   = {2015}
}

Comments

5 pages, 1 figure, 1 table

R2 v1 2026-06-21T20:00:16.307Z