"Certain interactions, such as nuclear forces and the forces of 'high-energy' physics, which arise in the theory of elementary particles, cannot be described successfully by quantum field theory. Considerable interest has therefore centred on attempts to formulate interactions between elementary particles in terms of the S-Matrix, an operator introduced by Heisenberg which connects the input and output of a scattering experiment without ..."
Renormalization(Reprint) An Introduction to Renormalization, the Renormalization Group and the Operator-Product Expansion (Cambridge Monographs on Mathematical Physics) by John Clements Collins , Peter Landshoff , D. R. Nelson Paperback, 392 Pages, Published 1986 by Cambridge University Press ISBN-13: 978-0-521-31177-9, ISBN: 0-521-31177-2