Journal article
Analytic two-loop form factors in N=4 SYM
Journal of High Energy Physics, (5)
May/2012
Abstract
We derive a compact expression for the three-point MHV form factors of half-BPS operators in N - 4 super Yang-Mills at two loops. The main tools of our calculation are generalised unitarity applied at the form factor level, and the compact expressions for supersymmetric tree-level form factors and amplitudes entering the cuts. We confirm that infrared divergences exponentiate as expected, and that collinear factorisation is entirely captured by an ABDK/BDS ansatz. Next, we construct the two-loop remainder function obtained by subtracting this ansatz from the full two-loop form factor and compute it numerically. Using symbology, combined with various physical constraints and symmetries, we find a unique solution for its symbol. With this input we construct a remarkably compact analytic expression for the remainder function, which contains only classical polylogarithms, and compare it to our numerical results. Furthermore, we make the surprising observation that our remainder is equal to the maximally transcendental piece of the two-loop Higgs plus three-gluon scattering amplitudes in QCD.
Details
- Title
- Analytic two-loop form factors in N=4 SYM
- Creators
- Andreas Brandhuber (null) - The Weizmann Institute of ScienceGabriele Travaglini (null)Gang Yang (null)
- Resource Type
- Journal article
- Publication Details
- Journal of High Energy Physics, (5); May/2012
- Number of pages
- 33
- Language
- English
- DOI
- https://doi.org/10.1007/JHEP05(2012)082
- Grant note
- STFC [ST/J000469/1]; German Science Foundation (DFG) within the Collaborative Research Center 676; Institute for Particle Physics Phenomenology, Durham University; Weizmann Institute of ScienceWe would like to thank Zvi Bern, Rutger Boels, Paul Heslop, Valya Khoze, Lorenzo Magnea and Bill Spence for illuminating discussions. This work was supported by the STFC Grant ST/J000469/1, "String theory, gauge theory & duality", and by the German Science Foundation (DFG) within the Collaborative Research Center 676 "Particles, Strings and the Early Universe". AB thanks the "Feinberg Foundation Visiting Faculty Program at the Weizmann Institute of Science and Tel Aviv University for hospitality. GT acknowledges the warm hospitality and support from the Institute for Particle Physics Phenomenology, Durham University, through an IPPP Associateship, as well as from the Weizmann Institute of Science._ALMAME_DELIMITER_
- Scientific Unit
- The Weizmann Institute of Science
- Record Identifier
- 993266000803596
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