Pion-nucleus inelastic scattering and charge exchange

Abstract

Using a separable fixed scatterer pion-nucleon interaction and the distorted wave impulse approximation we have made predictions for medium energy pion inelastic scattering from 16O and ( π −, π 0) charge exchange from 48Ca. An optical potential based on the pion-nucleon interaction adopted in this work has been shown previously to provide good fits to pion-nucleus elastic scattering. After a discussion of the basic formulae, we present results of calculations for pion inelastic scattering from 16O for initial pion lab kinetic energies of 70 and 180 MeV. Because of the strong energy dependence of the pion-nucleon interaction there are qualitative differences between the predictions for the nuclear response in the momentum transfer, energy loss plane for T π lab = 70 and 180 MeV. At these energies, states not prominently excited by other probes are predicted to be observable. In particular, J π = 3 − and 4 −, T = 0 states appear prominently in the excitation spectrum region at large momentum transfer. A comparison of π − and π + scattering showing the effects of the Coulomb interaction is presented. The predictions for pion single-charge exchange on 48Ca indicate that this interaction would be useful for studying the location of the T > states arising from the splitting of the giant dipole resonance in T ≠ 0 nuclei.