Large gauge symmetries and asymptotic states in QED

Barak Gabai, Amit Sever

Research output: Contribution to journalArticlepeer-review

Abstract

Large Gauge Transformations (LGT) are gauge transformations that do not vanish at infinity. Instead, they asymptotically approach arbitrary functions on the conformal sphere at infinity. Recently, it was argued that the LGT should be treated as an infinite set of global symmetries which are spontaneously broken by the vacuum. It was established that in QED, the Ward identities of their induced symmetries are equivalent to the Soft Photon Theorem. In this paper we study the implications of LGT on the S-matrix between physical asymptotic states in massive QED. In appose to the naively free scattering states, physical asymptotic states incorporate the long range electric field between asymptotic charged particles and were already constructed in 1970 by Kulish and Faddeev. We find that the LGT charge is independent of the particles’ momenta and may be associated to the vacuum. The soft theorem’s manifestation as a Ward identity turns out to be an outcome of not working with the physical asymptotic states.

Original languageEnglish
Article number95
JournalJournal of High Energy Physics
Volume2016
Issue number12
DOIs
StatePublished - 1 Dec 2016

Keywords

  • Gauge Symmetry
  • Global Symmetries
  • Scattering Amplitudes
  • Spontaneous Symmetry Breaking

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics

Fingerprint

Dive into the research topics of 'Large gauge symmetries and asymptotic states in QED'. Together they form a unique fingerprint.

Cite this