Long-distance singularities in multi-leg scattering amplitudes

Einan Gardi, Oyvind Almelid, Claude Duhr

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract / Description of output

We report on the recent completion of the three-loop calculation of the soft anomalous dimension in massless gauge-theory scattering amplitudes. This brings the state-of-the-art knowledge of long-distance singularities in multi-leg QCD amplitudes with any number of massless particles to three loops. The result displays some novel features: this is the first time non-dipole corrections appear, which directly correlate the colour and kinematic degrees of freedom of four coloured partons. We find that non-dipole corrections appear at three loops also for three coloured partons, but these are independent of the kinematics. The final result is remarkably simple when expressed in terms of single-valued harmonic polylogarithms, and it satisfies several non-trivial constraints. In particular, it is consistent with the high-energy limit behaviour and it satisfies the expected factorization properties in two-particle collinear limits.
Original languageEnglish
Title of host publicationProceedings, 13th DESY Workshop on Elementary Particle Physics: Loops and Legs in Quantum Field Theory (LL2016) : Leipzig, Germany, April 24-29, 2016
PublisherPoS - Proceedings of Science
Number of pages15
Publication statusPublished - 20 Oct 2016

Publication series

PublisherProceedings of Science
ISSN (Print)1824-8039


Dive into the research topics of 'Long-distance singularities in multi-leg scattering amplitudes'. Together they form a unique fingerprint.

Cite this