Towards two-loop automation in OpenLoops
NLO scattering amplitudes are provided by fully automated numerical tools, such as OpenLoops, for a very wide range of processes. In order to match the numerical precision of current and future collider experiments, the higher precision of NNLO calculations is essential, and their automation in a si...
Saved in:
Main Authors | , , |
---|---|
Format | Journal Article |
Language | English |
Published |
15.07.2022
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | NLO scattering amplitudes are provided by fully automated numerical tools,
such as OpenLoops, for a very wide range of processes. In order to match the
numerical precision of current and future collider experiments, the higher
precision of NNLO calculations is essential, and their automation in a similar
tool a highly desirable goal. In our approach, D-dimensional two-loop
amplitudes are decomposed into Feynman integrals with four-dimensional
numerators and (D-4)-dimensional remainders. The latter are reconstructed
through process-independent rational counterterm insertions into lower-loop
diagrams, while the first are expressed as loop momentum tensor integrals
contracted with tensor coefficients. In this article, we describe a completely
generic algorithm, first presented in [1], for the efficient and numerically
stable construction of these tensor coefficients. This algorithm is fully
implemented in the OpenLoops framework for QED and QCD corrections to the
Standard Model. For this implementation we present performance studies on
numerical stability and CPU efficiency. |
---|---|
Bibliography: | PSI-PR-22-23 |
DOI: | 10.48550/arxiv.2207.07468 |