@article{50391266192846138d0b47a63dee644d,
title = "Perturbation Theory at Eight Loops: Novel Structures and the Breakdown of Manifest Conformality in N=4 Supersymmetric Yang-Mills Theory",
abstract = "We use the soft-collinear bootstrap to construct the 8-loop integrand for the 4-point amplitude and 4-stress-tensor correlation function in planar maximally supersymmetric Yang-Mills theory. Both have a unique representation in terms of planar, conformal integrands grouped according to a hidden symmetry discovered for correlation functions. The answer we find exposes a fundamental tension between manifest locality and planarity with manifest conformality not seen at lower loops. For the first time, the integrand must include terms that are finite even on-shell and terms that are divergent even off-shell (so-called pseudoconformal integrals). We describe these novelties and their consequences in this Letter, and we make the full correlator and amplitude available as part of the Supplemental Material.",
author = "Bourjaily, {Jacob L.} and Paul Heslop and Tran, {Vuong Viet}",
note = "Funding Information: The authors gratefully acknowledge the insights shared through conversations with Simon Caron-Huot, Burkhard Eden, Gregory Korchemsky, Emery Sokatchev, Marcus Spradlin, and Jaroslav Trnka, and the custom computer code provided by Simon Caron-Huot for fast numerical evaluation. This work was supported in part by the Harvard Society of Fellows, a grant by the Harvard Milton Fund, and MOBILEX grant from the Danish Council for Independent Research (J. L. B.); a STFC studentship (V.-V. T.); and a STFC Consolidated Grant No. ST/L000407/1 and the Marie Curie network GATIS of the European Union's Seventh Framework Programme FP7/2007-2013/ under REA Grant Agreement No. 317089 (P. H.). Publisher Copyright: {\textcopyright} 2016 American Physical Society.",
year = "2016",
month = may,
day = "11",
doi = "10.1103/PhysRevLett.116.191602",
language = "English (US)",
volume = "116",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "19",
}