Direct numerical approach to one-loop amplitudes

Abstract

We present a completely numerical method of calculating one-loop amplitudes. Our approach is built upon two different existing methods: the contour deformation and the extrapolation methods. Taking the best features of each of them, we devise an intuitive, stable and robust procedure which circumvents the problem of large cancellations and related numerical instabilities by calculating the complete amplitude at once. As a proof of concept, we use our method to calculate the $2\gamma \to (N-2)\gamma$ benchmark process, as well as the Higgs decay amplitude $H\to \gamma \gamma$.

9 pages, 8 figures, expanded version accepted for publication in Phys Rev D

References in corpus (5)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• GoSam-2.0: a tool for automated one-loop calculations within the Standard Model and beyond
• Numerical integration of one-loop Feynman diagrams for N-photon amplitudes
• Numerical NLO QCD calculations
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Cited by in corpus (3)

• RECOLA: REcursive Computation of One-Loop Amplitudes
• Recola2: REcursive Computation of One-Loop Amplitudes 2
• Collider Physics at the Precision Frontier