Elastic scattering of pions from tritium and helium-3 in the backward hemisphere, in the region of the Delta(33)(1232) resonance

Several experiments have measured nominally-charge-symmetric scattering of pions from tritium ({dollar}sp3{dollar}H) and {dollar}sp3{dollar}He. These experiments have covered incident pion energies from 142 MeV to 295 MeV and scattering angles up to 110{dollar}spcirc{dollar} in the laboratory. The results have been used to study charge-symmetry breaking and nuclear scattering systematics.; In this work I have extended these measurements to angles near 180{dollar}spcirc{dollar} for pion energies of 142 MeV, 180 MeV, 220 MeV, and 256 MeV, which bracket the {dollar}Deltasb{lcub}33{rcub}{dollar} pion-nucleon resonance. This is the most extensive set of {dollar}pi{dollar}T and {dollar}pisp3{dollar}He data in this kinematical region. It will allow tests of scattering theory of pion-nucleus interactions and charge-symmetry breaking in back-angle scattering, and, within the limits of these two theories, it may help improve our understanding of the structure of these nuclei.