Analysis ofπ±−C12elastic scattering

Abstract

We present an analysis of ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{-}^{12}\mathrm{C}$ elastic scattering by using a phenomenological ansatz for the pure hadronic amplitude; in addition a careful treatment of Coulomb effects has turned out to be essential. The resulting phase shifts and inelasticity parameters show a smooth behavior in the entire energy region between ${T}_{\ensuremath{\pi}}=30$ and 230 MeV. The rapid increase of the differential cross sections at backward angles (${T}_{\ensuremath{\pi}}=162$ MeV) is discussed in terms of a semiclassical theory of the nuclear glory effect and is well reproduced by using additional information on analytic structure of the $\ensuremath{\pi}\ensuremath{-}^{12}\mathrm{C}$ elastic scattering amplitude in the complex $t$ plane.[NUCLEAR REACTIONS $^{12}\mathrm{C}({\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}},{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}})^{12}\mathrm{C}$, $E=30\ensuremath{-}226$ MeV.]