Scattering and reflection positivity in relativistic Euclidean quantum mechanics

Abstract: In this paper I discuss a formulation of relativistic few-particle scattering theory where the dynamical input is a collection of reflection-positive Euclidean covariant Green functions. This formulation of relativistic quantum mechanics has the advantage that all calculations can be performed using Euclidean variables. The construction of the Hilbert space inner product requires that the Green functions are reflection positive, which is a non-trivial constraint on the dynamics. In this paper I discuss the structure of reflection positive Green functions. I show that scattering wave operators exist when the dynamics is given by a Green function with the structure discussed in this work. Techniques for computing scattering observables in this Euclidean framework are discussed.