Full one-loop amplitudes from tree amplitudes

By W. Giele, Z. Kunszt, K. Melnikov. 2008

293 citations recorded by the source corpus.

We establish an efficient polynomial-complexity algorithm for one-loop calculations, based on generalized D-dimensional unitarity. It allows automated computations of both cut-constructible and rational parts of one-loop scattering amplitudes from on-shell tree amplitudes. We illustrate the method by (re)-computing all four-, five- and six-gluon scattering amplitudes in QCD at one-loop.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/2782fa32dff1f258801ec8b41f1a103864ae3b57

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In Nuclear and High Energy Physics

Citations in the corpus

GoSam-2.0: a tool for automated one-loop calculations within the Standard Model and beyond (2014, methodology): “ external momenta or polarization vectors constructed out of them. GoSam is a code which was designed to maximally exploit both the integrand reduction for dimensionally regulated one-loop amplitudes [16,24], as implemented in Samurai [25], as well as improved tensor reduction methods as developed i”
The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations (2014, methodology): “The two methods which have been used for complicated numerical simulations are bootstrap [17] and D-dimensional unitarity [19,20,23].”
A two-loop five-gluon helicity amplitude in QCD (2013, background): “If Ds > D, a careful consideration [7, 63] shows that each of the (Ds − D) higher dimensional components will act as a scalar-like particle, which behaves just like the coloured scalars known from N = 4 super Yang-Mills.”
Scattering amplitudes from unitarity-based reduction algorithm at the integrand-level (2010, methodology): “we implement a semi-numerical algorithm whose main features are: – 5 – •the extension of the OPP-polynomials [80,89] for quadruple-, triple- and double-cut to the framework of d-dimensional unitarity [87,88]; •the parametrization of the residue of the quintuple-cut aﬀecting only the polynomial depen”
Constraining anomalous Higgs boson couplings to the heavy flavor fermions using matrix element techniques (2016, methodology): “We calculate the virtual correction to the gg and qq̄ initial states using the numerical implementation of D-dimensional generalized unitarity techniques [69–72].”
Scattering amplitudes over finite fields and multivariate functional reconstruction (2016, unknown): “The problem can be mitigated by the use of computer algebra systems such as Form [22], which specializes in handling large expressions, or by using techniques such as generalized unitarity [23,24], where intermediate steps of the calculation are gauge invariant and hence the complexity of their expr”