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

By G. Ossola, Costas G. Papadopoulos, R. Pittau. 2007

475 citations recorded by the source corpus.

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 -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.

Subfields: Artificial Intelligence, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/176295a20fc2a3a2e75c58329347fb03193aae68

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Citations in the corpus

Automation of one-loop QCD computations (2011, background): “Tools [31] which, being given in input the function N(l), the momenta defined in the partial sums of eq.”
Large NLO corrections in tt¯ W ± and tt¯ tt¯ hadroproduction from supposedly subleading EW contributions (2018, methodology): “These techniques have been automated in the module MadLoop [10], which is used for the generation of the amplitudes and in turn exploits CutTools [53], Ninja [54, 55] and Collier [56], together with an in-house implementation of the OpenLoops optimisation [5].”
NLO electroweak automation and precise predictions for W + multijet production at the LHC (2014, methodology): “Alternatively, the reduction of (3.1) to scalar integrals can be performed at the integrand level using the OPP method [88] as implemented in CutTools [89] or Samurai [90], which both rely on the OneLOop library [91] for the evaluation of scalar integrals.”
Fully differential NNLO computations with MATRIX (2017, methodology): “cluster_submit_line[1-99] Lines in cluster submit file to add cluster-specific options.”
A framework for Higgs characterisation (2013, methodology): “MadLoop [64] computes the one-loop amplitudes, using the OPP [65] integrand-reduction method and its implementation in CutTools [66].”
Electroweak and QCD corrections to top-pair hadroproduction in association with heavy bosons (2015, methodology): “– 3 – procedures for the computation of the one-loop matrix elements (automated in the module MadLoop [20, 33], which makes use of CutTools [45] with OPP and of IREGI [46] with TIR, and of an in-house implementation of the representation proposed in ref.”
MadGraph 5: going beyond (2011, methodology): “Very recently, CutTools [31] has been successfully interfaced with MadGraph .”
Handbook of LHC Higgs Cross Sections: 3. Higgs Properties (2013, methodology): “This is a non-trivial check, also taking into account that P OWHEL, like HELAC-NLO, uses the OPP method [133, 134] complemented by rational terms of kind R2 [198] to compute one-loop amplitudes, whereas the authors of [184] rely on tensor-reduction techn iques.”
W±Z production at the LHC: fiducial cross sections and distributions in NNLO QCD (2016, methodology): “ two independent tensor-reduction implementations of Collier disagree by more than a certain threshold | OpenLoops provides a rescue system based on the quadruple-precision implementation of CutTools [50], which applies scalar integrals from OneLOop [51]. For the two-loop helicity amplitudes we rely”
The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations (2014, methodology): “We list all of them here: ALOHA [92], CutTools [156], FastJet (core) [376], HELAS [91], HERWIG6 [142], – 137 – MINT [171], OneLoop [371], Pythia6 [141], QCDloop [372], RAMBO [377], StdHEP [378], Vegas [379,380].”
Electroweak radiative corrections for collider physics (2019, methodology): “The results for the contributions of the 4-point functions are slightly more complicated and involve (q̌2)2 terms [197, 239].”
Recursive generation of one-loop amplitudes in the Standard Model (2012, background): “These are overcome by computing the amplitude in quadruple or multiple precision at critical phase-space points, reducing however the CPU efficiency [41, 42].”