Infrared and transcendental structure of two-loop supersymmetric QCD amplitudes
- Journal Article
Rights / licenseCreative Commons Attribution 4.0 International
Using a careful choice of infrared (IR) subtraction scheme, we demonstrate cancellation of all terms with transcendental weights 0, 1, 2 from the finite part of the full-color two-loop four-gluon N = 2 supersymmetric QCD amplitude, with Nf massless supersymmetric quarks. This generalizes the previously observed cancellation of weight-2 terms in the superconformal theory, where Nf = 2Nc for gauge group SU(Nc). The subtraction scheme follows naturally both from general IR factorization principles and from an integrand-level analysis of divergences in this amplitude. The divergences are written in terms of scalar triangle integrals whose expressions are known to all orders in the dimensional regulator ϵ = (4 − D)/2. We also present integrated expressions for the full-color two-loop four-point amplitudes with both matter and vectors on external legs in which lower-weight terms also cancel using an appropriate IR scheme. This provides us with values for the two-loop cusp, gluonic, and quark anomalous dimensions in N = 2 supersymmetric QCD, which are cross-checked between the three different amplitudes. Show more
Journal / seriesJournal of High Energy Physics
Pages / Article No.
SubjectScattering Amplitudes; Supersymmetric Gauge Theory
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