Excitation of the1+state inCa48(10.2 MeV) by inelastic scattering ofπ−andπ+

Abstract

Excitation functions for inelastic scattering of ${\ensuremath{\pi}}^{\ensuremath{-}}$ from $^{48}\mathrm{Ca}$ to the ${1}^{+}$ state at 10.2 MeV have been measured at constant momentum transfer $q=73$ MeV/c. The incident energy was varied between 116 and 180 MeV. An upper limit was measured for the ${\ensuremath{\pi}}^{+}$ cross section at 116 MeV. The data are not fitted by distorted-wave impulse approximation calculations at this $q$ where the differential cross section is predicted to have its maximum. The discrepancy between theory and experiment is similar to the disagreement observed for $^{12}\mathrm{C}(\ensuremath{\pi},{\ensuremath{\pi}}^{\ensuremath{'}})^{12}\mathrm{C}({1}^{+},15.1 \mathrm{MeV})$.