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arXiv · hep-ph/0609191

D-dimensional unitarity cut method

Charalampos Anastasiou·Ruth Britto·Bo Feng·Zoltan Kunszt·Pierpaolo Mastrolia
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Abstract

We develop a unitarity method to compute one-loop amplitudes with massless propagators in d=4-2*epsilon dimensions. We compute double cuts of the loop amplitudes via a decomposition into a four-dimensional and a -2*epsilon-dimensional integration. The four-dimensional integration is performed using spinor integration or other efficient techniques. The remaining integral in -2*epsilon dimensions is cast in terms of bubble, triangle, box, and pentagon master integrals using dimensional shift identities. The method yields results valid for arbitrary values of epsilon.

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Charalampos Anastasiou, Ruth Britto, Bo Feng, Zoltan Kunszt, Pierpaolo Mastrolia. 2006-09-27. D-dimensional unitarity cut method. https://doi.org/10.1016/j.physletb.2006.12.022

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