Decoherent scattering of light particles in a D-brane background

We discuss the scattering of two light particles in a D -brane background. It is known that, if one light particle strikes the D brane at small impact parameter, quantum recoil effects induce entanglement entropy in both the excited D brane and the scattered particle. In this paper we compute the asymptotic ‘out’ state of a second light particle scattering off the D brane at large impact parameter, showing that it also become s mixed as a consequence of quantum D -brane recoil effects. We interpret this as a non-factorizin g contribution to the superscattering operator /S for the two light particles in a Liouville D -brane background, that appears when quantum D -brane excitations are taken into account.