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Title: Avoidance of a Landau pole by flat contributions in QED

We consider massless Quantum Electrodynamics in the momentum scheme and carry forward an approach based on Dyson–Schwinger equations to approximate both the β-function and the renormalized photon self-energy (Yeats, 2011). Starting from the Callan–Symanzik equation, we derive a renormalization group (RG) recursion identity which implies a non-linear ODE for the anomalous dimension and extract a sufficient but not necessary criterion for the existence of a Landau pole. This criterion implies a necessary condition for QED to have no such pole. Solving the differential equation exactly for a toy model case, we integrate the corresponding RG equation for the running coupling and find that even though the β-function entails a Landau pole it exhibits a flat contribution capable of decreasing its growth, in other cases possibly to the extent that such a pole is avoided altogether. Finally, by applying the recursion identity, we compute the photon propagator and investigate the effect of flat contributions on both spacelike and timelike photons. -- Highlights: •We present an approach to approximate both the β-function and the photon self-energy. •We find a sufficient criterion for the self-energy to entail the existence of a Landau pole. •We study non-perturbative ‘flat’ contributions that emerge within the contextmore » of our approach. •We discuss a toy model and how it is affected by flat contributions.« less
Authors:
 [1] ;  [2]
  1. Department of Physics, Humboldt University Berlin, 12489 Berlin (Germany)
  2. Alexander von Humboldt Chair in Mathematical Physics, Humboldt University, Berlin 12489 (Germany)
Publication Date:
OSTI Identifier:
22314810
Resource Type:
Journal Article
Resource Relation:
Journal Name: Annals of Physics (New York); Journal Volume: 344; Journal Issue: Complete; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ANOMALOUS DIMENSION; APPROXIMATIONS; COUPLING; DIFFERENTIAL EQUATIONS; NONLINEAR PROBLEMS; PHOTONS; PROPAGATOR; QUANTUM ELECTRODYNAMICS; RENORMALIZATION; SCHWINGER FUNCTIONAL EQUATIONS; SELF-ENERGY