Manifest causality in quantum field theory with sources and detectors
High Energy Physics - Theory
2014-06-17 v3 High Energy Physics - Phenomenology
Abstract
We introduce a way to compute scattering amplitudes in quantum field theory including the effects of particle production and detection. Our amplitudes are manifestly causal, by which we mean that the source and detector are always linked by a connected chain of retarded propagators. We show how these amplitudes can be derived from a path integral, using the Schwinger-Keldysh "in-in" formalism. Focussing on phi-cubed theory, we confirm that our approach agrees with the standard S-matrix approach in the case of positive energy plane-wave scattering.
Keywords
Cite
@article{arxiv.1312.3871,
title = {Manifest causality in quantum field theory with sources and detectors},
author = {Robert Dickinson and Jeff Forshaw and Peter Millington and Brian Cox},
journal= {arXiv preprint arXiv:1312.3871},
year = {2014}
}
Comments
24 pages; 6 figures; version accepted for publication in JHEP