Research in theoretical particle physics will explore the emerging interface between superstring theory and quantum field theories of elementary particles. The implications of string theory for quantum field theories, and of exact solutions of quantum field theories for string theory, will be studied in detail. Specific research areas will include phase transitions and symmetry breaking, within the context of exactly solvable quantum field theories. The quantum field theories in question are natural extensions of the theories describing quarks and gluons, and are of great phenomenological as well as theoretical interest. Their high degree of solvability makes it possible to address a number of central yet otherwise-intractible questions about elementary particles.