Scattering-theory sensitivity analysis for spatial Hamiltonian variations

An expression for the functional-derivative sensitivity density of the scattering matrix in parameter space is derived. This expression can be used to assess the effect on scattering observables of varying space-dependent quantities in the Hamiltonian (e.g., the interaction potential or the free-target portion of the Hamiltonian). This work represents the most general formulation of elementary sensitivity analysis for quantum scattering problems, and its use is demonstrated by a few sample calculations.