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arXiv · hep-th/0506126

Two-Loop Amplitudes of Gluons and Octa-Cuts in N=4 Super Yang-Mills

Evgeny I. Buchbinder·Freddy Cachazo
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Abstract

After reduction techniques, two-loop amplitudes in N=4 super Yang-Mills theory can be written in a basis of integrals containing scalar double-box integrals with rational coefficients, though the complete basis is unknown. Generically, at two loops, the leading singular behavior of a scalar double box integral with seven propagators is captured by a hepta-cut. However, it turns out that a certain class of such integrals has an additional propagator-like singularity. One can then formally cut the new propagator to obtain an octa-cut which localizes the cut integral just as a quadruple cut does at one-loop. This immediately gives the coefficient of the scalar double box integral as a product of six tree-level amplitudes. We compute, as examples, several coefficients of the five- and six-gluon non-MHV two-loop amplitudes. We also discuss possible generalizations to higher loops.

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Evgeny I. Buchbinder, Freddy Cachazo. 2005-09-12. Two-Loop Amplitudes of Gluons and Octa-Cuts in N=4 Super Yang-Mills. https://doi.org/10.1088/1126-6708%2F2005%2F11%2F036

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