Unitarity sum rules and soft-pion amplitudes

C. Rosenzweig, G. Veneziano

Research output: Contribution to journalArticle

10 Scopus citations

Abstract

We examine unitarity bounds on scattering amplitudes by using « unitarity sum rules » at high energy. Threshold conditions emerge when certain mass parameters approach zero. For ππ scattering a bound similar to (but somewhat weaker than) the Adler condition is shown to be needed in order to avoid a dangerous mass (infra-red) singularity. A different argument, which uses crucially the pseudoscalar nature of the pion and a few very plausible dynamical assumptions, yields a stronger bound as well as the possibility of extension to general pion amplitudes. We finally discuss our results as well as the possibility of understanding spontaneously broken symmetries from general S-matrix principles.

Original languageEnglish (US)
Pages (from-to)409-424
Number of pages16
JournalIl Nuovo Cimento A Series 11
Volume12
Issue number2
DOIs
StatePublished - Nov 1 1972

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Nuclear and High Energy Physics
  • Astronomy and Astrophysics

Fingerprint Dive into the research topics of 'Unitarity sum rules and soft-pion amplitudes'. Together they form a unique fingerprint.

  • Cite this