The primary objective of this U.S.-Hungary cooperative research project between Dr. Colston Chandler of the University of Mexico and Dr. Gyula Bencze of the Central Research Institute for Physics, Budapest, is to determine how various approximate methods for N-body systems can be understood in the context of general quantum scattering theory. Work will build upon analyses of equations for systems of two and three charged particles in an effort to provide formulas for numerical expressions in few-body physics. Results of the joint research should yield reliable methods for quantitatively describing a larger class of multichannel scattering processes. This project in theoretical physics fulfills the program objective of advancing scientific knowledge by enabling leading experts in the United States and Eastern Europe to combine complementary talents and pool research resources in areas of strong mutual interest and competence.