We analyze scattering into a double-slit interferometer with target-fragmen
t recoil detection as a monitor of quantum correlation and entanglement in
few-body reaction amplitudes. We thus investigate two-slit interference wit
h which-way information as an enhancement to modern reaction-fragment detec
tion. We briefly consider charged-particle scattering with recoil-ion detec
tion from the point of view of quantum information.