Isobaric-analog-state transitions in pion charge-exchange reactions above the Δ(1232) resonance

Forward-angle differential cross sections for the (π⁺, π⁰) reaction to isobaric analog states were measured at 300, 425, 500, and 550 MeV on targets ranging in mass from ⁷Li to ²⁰⁸Pb. The 0° cross sections are found to rise markedly between 300 and 425 MeV, contrary to the behavior of the free πN process. The mass and energy dependence of the cross sections at the higher energies are discussed within the framework of the Glauber model.