European Physical Journal C: Particles and Fields (Jan 2019)

Unveiling regions in multi-scale Feynman integrals using singularities and power geometry

  • B. Ananthanarayan,
  • Abhishek Pal,
  • S. Ramanan,
  • Ratan Sarkar

DOI
https://doi.org/10.1140/epjc/s10052-019-6533-x
Journal volume & issue
Vol. 79, no. 1
pp. 1 – 20

Abstract

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Abstract We introduce a novel approach for solving the problem of identifying regions in the framework of Method of Regions by considering singularities and the associated Landau equations given a multi-scale Feynman diagram. These equations are then analyzed by an expansion in a small threshold parameter via the Power Geometry technique. This effectively leads to the analysis of Newton Polytopes which are evaluated using a Mathematica based convex hull program. Furthermore, the elements of the Gröbner Basis of the Landau Equations give a family of transformations, which when applied, reveal regions like potential and Glauber. Several one-loop and two-loop examples are studied and benchmarked using our algorithm which we call ASPIRE.