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arXiv · 0711.3596

CutTools: a program implementing the OPP reduction method to compute one-loop amplitudes

Giovanni Ossola·Costas G. Papadopoulos·Roberto Pittau
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Abstract

We present a program that implements the OPP reduction method to extract the coefficients of the one-loop scalar integrals from a user defined (sub)-amplitude or Feynman Diagram, as well as the rational terms coming from the 4-dimensional part of the numerator. The rational pieces coming from the epsilon-dimensional part of the numerator are treated as an external input, and can be computed with the help of dedicated tree-level like Feynman rules. Possible numerical instabilities are dealt with the help of arbitrary precision routines, that activate only when needed.

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Giovanni Ossola, Costas G. Papadopoulos, Roberto Pittau. 2008-04-07. CutTools: a program implementing the OPP reduction method to compute one-loop amplitudes. https://doi.org/10.1088/1126-6708%2F2008%2F03%2F042

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