Three particle singularities in scattering amplitudes
As a preliminary to a study of the three particle case, a detailed discussion is given, within the framework of the S-matrix postulates of unitarity and analyticity, of methods of defining “reduced” two particle scattering amplitudes that lack the two particle singularity; the extension to the multichannel case is briefly described. The same methods are used to remove one, two, and three particle physical threshold singularities from a three particle scattering amplitude. Using a causality argument, a derivation is given of the iϵ prescription for all these singularities.
This main objectives of this effort are the development and prototyping of a small. sensitive, and low-cost multi-channel nanoparticle scintillation microdevice with integrated waveguides for alpha, beta, gamma, and neutron detection. This research effort has integrated experiments and simulation to determine the combination of process-specific materials for the achievement optimum detection conditions.