Energy-dependent correction to the plane-wave impulse approximation

The scattering amplitude in the plane-wave impulse approximation is extended to second order in the collision time tau. This extension results in a correction proportional to E0-1, where E0 is the incident particle energy. The experimental values of the peak auasi-free scattering cross sections for the knockout reactions 2H(p,2p), 2H(p,pn), 2H(αp), 3He(p,2p), and 4He(p,2p) are shown to deviate from the plane-wave impulse approximation as E0-1, in agreement with this theory