  Memory effects in scattering processes are described in terms of the
asymptotic retarded fields. These fields are completely determined by the
scattering data and the zero mode part is set by the soft photon theorem. The
dressed asymptotic states defining an infrared finite S- matrix for charged
particles can be defined as quantum coherent states using the corpuscular
resolution of the asymptotic retarded fields. Im- posing that the net radiated
energy in the scattering is zero leads to the new set of conservation laws for
the scattering S-matrix which are equivalent to the decoupling of the soft
modes. The actual observabil- ity of the memory requires a non vanishing
radiated energy and could be described using the infrared part of the
differential cross section that only depends on the scattering data and the
radiated energy. This is the IR safe cross section with any number of emitted
pho- tons carrying total energy equal to the energy involved in the actual
memory detection.
