English

Constructing multi-loop scattering amplitudes with manifest singularity structure

High Energy Physics - Theory 2019-07-22 v3 High Energy Physics - Phenomenology

Abstract

The infrared exponentiation properties of dimensionally-regularized multi-loop scattering amplitudes are typically hidden at the level of the integrand, materializing only after integral evaluation. We address this long-standing problem by introducing an appropriate integral basis which is simultaneously finite and uniform weight. As an example, we cast the integrand for the QCD corrections to the two-loop massless quark electromagnetic form factor into a form where it is manifest that the ϵ4\epsilon^{-4} and ϵ3\epsilon^{-3} pole terms arise from the ϵ\epsilon expansion of the square of our one-loop master integral.

Keywords

Cite

@article{arxiv.1806.05682,
  title  = {Constructing multi-loop scattering amplitudes with manifest singularity structure},
  author = {Robert M. Schabinger},
  journal= {arXiv preprint arXiv:1806.05682},
  year   = {2019}
}

Comments

8 pages; in v2: references added relative to v1; in v3: introduction expanded and examples added along the lines suggested by the referees, further references and note added