A new path-integral representation of the T-matrix in potential scattering

► We derive a new path-integral representation for the T-matrix in quantum scattering from a potential. ► The method is based on a technique used by Barbashov and collaborators in Quantum Field Theory. ► Unlike previous approaches no unphysical degrees of freedom in the path integral are needed. ► The new representation is used for a variational approximation of the T-matrix at high energies. ► A new expression for the scattering length at low energy is derived.