English

Optical theorem and effective action: new proofs of old results in QFT

High Energy Physics - Theory 2020-06-01 v1

Abstract

A new proof of the optical theorem at all orders is presented. Although the theorem is a well-known result in Quantum Field Theory, our proof is interesting because it is particularly simple. Indeed, the theorem is a direct consequence of the pole-ology formalism discussed in Weinberg's Cambridge books. We also discuss a new proof of the standard result concerning the effective action as generating functional of 1PI contributions.

Keywords

Cite

@article{arxiv.2005.14558,
  title  = {Optical theorem and effective action: new proofs of old results in QFT},
  author = {Sergio L. Cacciatori and Andrea Zanzi},
  journal= {arXiv preprint arXiv:2005.14558},
  year   = {2020}
}

Comments

5 pages; suitable for degree students tackling QFT