The propagator seagull: general evaluation of a two loop diagram

  • Barak Kol
  • Ruth ShirEmail author
Open Access
Regular Article - Theoretical Physics


We study a two loop diagram of propagator type with general parameters through the Symmetries of Feynman Integrals (SFI) method. We present the SFI group and equation system, the group invariant in parameter space and a general representation as a line integral over simpler diagrams. We present close form expressions for three sectors, each with three or four energy scales, for any spacetime dimension d as well as the ϵ expansion. We determine the singular locus and the diagram’s value on it.


Perturbative QCD Scattering Amplitudes 


Open Access

This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.


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Copyright information

© The Author(s) 2019

Authors and Affiliations

  1. 1.The Racah Institute of PhysicsThe Hebrew University of JerusalemJerusalemIsrael

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