Modelling nucleon-nucleon scattering above 1 GeV

Abstract

Motivated by the recent measurement of proton-proton spin-correlation parameters up to 2.5 GeV laboratory energy, we investigate models for nucleonnucleon (N N ) scattering above 1 GeV. Signatures for a gradual failure of the traditional meson model with increasing energy can be clearly identified.Since spin effects are large up to tens of GeV, perturbative QCD cannot be invoked to fix the problems. We discuss various theoretical scenarios and come to the conclusion that we do not have a clear phenomenological understanding of the spin-dependence of the N N interaction above 1 GeV.

Pion Production Data needed for Space Radiation

“…However, most of the data are at very high energy. In the intermediate energy region (1)(2)(3)(4)(5)(6)(7)(8)(9)(10), there are very few measurements of either total or differential cross sections. This is not a good situation for space radiation, since it is the inclusive cross sections in the intermediate energy region that are most often required.…”

“…Furthermore, the region where theory is least understood is 1 -10 GeV because intermediate energy is too high for non-relativistic models to work well and too low for ultrarelativistic approximations. This is made clear in the work of Eyser and Machleidt,3 who analyze spin correlation functions and show that the standard one boson exchange models, fail badly in explaining spin correlation cross section measurements. Nevertheless, they show that these models do work reasonably well when spin averages are taken into account.…”

“…for the Badhwar parametrization [3,4]. re mb/GeV 2 , GeV −1 , and GeV −2 , respecs are dimensionless.…”

Excitation functions of spin correlation parametersANN,ASS, andABauer1, Bisplinghoff2, Büßer3 et al. 2005Phys. Rev. CSelf Cite16010View full textAdd to dashboardCite

“…Up to 800 MeV sufficient data exist that still allow an unambiguous determination of phase shift parameters and that are reasonably well reproduced by extended meson exchange models [19]. For even higher energies the number of contributing partial waves increases, and at the same time are the data more scarce and inconsistent.…”

Proton-proton scattering above 3 GeV/c

“…The findings in Refs. [11,13] show that traditional nuclear models of the N N interaction such as meson-exchange potentials cannot be easily extended to the energies covered by the COSY-EDDA and SATURNE experiments. At the same time that region is much too low for perturbative QCD to be applied.…”