Pion-pion scattering above resonances

Abstract

We model large angle intermediate energy pion-pion scattering by the pQCD two-gluon (2g) exchange contribution and discuss the onset of the dominance of the Glauber-Gribov-Landshoff (GGL) component. The pQCD 2g exchange contribution becomes substantial already at $|t|\sim$ 1 GeV^{2}, but the pQCD exchange dominance is deferred to $|t|\sim$ 3 GeV^{2} because of competing multiple soft rescattering effects. Based on the NN and $\pi N$ total cross section data and Regge factorization, we evaluate the dominant soft contribution to the $\pi \pi$ total cross section and find the results consistent with the ones deduced earlier from the absorption model analysis of the $\pi N \to X N, X \Delta$ data.