A study of the Δ−-component of the wave function in light nuclei

Abstract We have measured cross sections for the ( π + , π ± p ) reactions on 3 H, 4 He, 6 Li and 7 Li in quasi-free kinematics at incident pion beam energy 500 MeV. An enhancement of the ( π + , π − p ) cross section in this kinematics is observed. If this is interpreted as due to quasi-free scattering from preexisting Δ components of the nuclear wave function, the extracted probabilities are in agreement with theoretical expectations.