Scattering amplitudes with open loops.

By F. Cascioli, P. Maierhöfer, Stefano Pozzorini. Physical Review Letters, 2011

1,468 citations recorded by the source corpus.

We introduce a new technique to generate scattering amplitudes at one loop. Traditional tree algorithms, which handle diagrams with fixed momenta, are promoted to generators of loop-momentum polynomials that we call open loops. Combining open loops with tensor-integral and Ossola-Papadopoulos-Pittau reduction results in a fully flexible, very fast, and numerically stable one-loop generator. As demonstrated with nontrivial applications, the open-loop approach will permit us to obtain precise predictions for a very wide range of collider processes.

Subfields: Electrical and Electronic Engineering, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/22640fe3355dff7a1bbe04ebf0ad94dee232b02a

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Citations in the corpus

Collier: A fortran-based complex one-loop library in extended regularizations (2016, methodology): “While the methods described so far are formulated in the literature in terms of the Lorentz-invariant coefficients TNi1...iP , a new generation of NLO generators, such as OpenLoops and Recola, needs the components of the full tensors TN,µ1···µP .”
NLO QCD corrections to off-shell top-antitop production with leptonic decays at hadron colliders (2012, methodology): “In addition, in presence of FwW effects we used OpenLoops [89] to evaluate the real-emission matrix elements in the complex-mass scheme.”
Les Houches 2017: Physics at TeV Colliders Standard Model Working Group Report (2017, methodology): “There has been progress towards a complete automation of NLOEW corrections within one-loop programs such as OpenLoops, GoSam, Recola, MadLoop and NLOX, which has led to the completion of many items from the 2013 list.”
Search for electroweak production of supersymmetric particles in final states with two or three leptons at \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\odd (2018, methodology): “The matrix elements containing all diagrams with four electroweak vertices with additional hard parton emissions were calculated with Comix [41] and virtual QCD corrections were calculated with OpenLoops [42].”
Weak corrections to Higgs hadroproduction in association with a top-quark pair (2014, neutral): “[67] (OpenLoops)).”
NLO electroweak automation and precise predictions for W + multijet production at the LHC (2014, methodology): “Its CPU efficiency is further augmented by means of parent-child relations and thanks to further tricks that exploit the systematic factorisation of colour-, helicity-, and q-dependent objects [44].”
Recursive generation of one-loop amplitudes in the Standard Model (2012, methodology): “J H E P 0 4 ( 2 0 1 3 ) 0 3 7 Recently the diagrammatic approach has been further boosted by the advent of the OpenLoops algorithm [57].”
W+W− production at the LHC: fiducial cross sections and distributions in NNLO QCD (2015, methodology): “For the numerically stable evaluation of tensor integrals, OpenLoops relies on the Collier library [32], which is based on the Denner–Dittmaier reduction techniques [33,34] and the scalar integrals of [35].”
Les Houches 2013: Physics at TeV Colliders: Standard Model Working Group Report (2014, methodology): “In the last two years, we have seen the NLO calculation of complex multi-leg processes such as for the production of 5 jets [1], W + 5 jets [2], and Higgs + 3 jets [3] as well as the further development of general purpose NLO codes such as GoSaM [4], HELAC-NLO [5], MadLoop [6], OpenLoops [7], and Re”
Higgs production in association with bottom quarks (2014, neutral): “[36] (OpenLoops)).”
Parton distributions from high-precision collider data (2017, methodology): “At NLO theoretical predictions have been generated with Sherpa [108], in a format compliant to APPLgrid [103], using the MCgrid code [109] and the Rivet [123] analysis package, with OpenLoops [124] for the NLO matrix elements.”
Search for the standard model Higgs boson produced in association with top quarks and decaying into a bb¯ pair in pp collisions at √s=13 TeV with the ATLAS detector (2018, methodology): “To model the dominant tt̄þ ≥ 1b background with the highest available precision, the relative contributions of the different subcategories, tt̄þ ≥ 3b, tt̄ þ bb̄, tt̄ þ B and tt̄ þ b, in the POWHEG+PYTHIA 8 sample described above are scaled to match those predicted by an NLO tt̄bb̄ sample including p”
The automation of next-to-leading order electroweak calculations (2018, methodology): “Indeed, although not as comprehensive as for QCD computations, there has been steady progress in the automation of EW NLO corrections, for both one-loop and realemission contributions, by collaborations such as RECOLA [8, 9] with Sherpa [10, 11], OpenLoops [12] with Sherpa, GoSam [13, 14] with eithe”
Event generation with Sherpa 2.2 (2019, methodology): “BLACKHAT [13], OPENLOOPS [14] and RECOLA [15, 16].”
Predictions for diphoton production at the LHC through NNLO in QCD (2016, methodology): “The alternate QT -slicing calculation is implemented using the Sherpa framework [68] and uses the OpenLoops [69] and BlackHat [70–72] programs to evaluate the above-cut matrix elements.”
OpenLoops 2 (2019, methodology): “In the original open-loop algorithm [9], the rank of open loops increases at each step of the recursion.”
Search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks using a matrix element method (2015, methodology): “The scattering amplitude for the hard process is evaluated numerically at LO accuracy by the program OPENLOOPS [66]; all resonances are treated in the narrow-width approximation [67], and spin correlations are neglected.”