Unitarity and the evaluation of discontinuities

Research paper by D. I. Olive

Indexed on: 22 Nov '07Published on: 22 Nov '07Published in: Il Nuovo Cimento (1955-1965)


If we call the connected part of theT-matrix element for the processb →a,, then we prove the following result. If is the boundary value of an analytic function of complex invariants, then is an opposite boundary value. This follows directly from field theory, is independent of any special invariance principles, or of crossing symmetry and is not restricted to any type of process. This result achieves validity in a much wider context than was previously believed, and emerges as a fundamental consequence of theTCP theorem. It means that unitarity provides a direct evaluation of the corresponding discontinuity.