Connected formulas for amplitudes in standard model

Abstract

Witten's twistor string theory has led to new representations of S-matrix in massless QFT as a single object, including Cachazo-He-Yuan formulas in general and connected formulas in four dimensions. As a first step towards more realistic processes of the standard model, we extend the construction to QCD tree amplitudes with massless quarks and those with a Higgs boson. For both cases, we find connected formulas in four dimensions for all multiplicities which are very similar to the one for Yang-Mills amplitudes. The formula for quark-gluon color-ordered amplitudes differs from the pure-gluon case only by a Jacobian factor that depends on flavors and orderings of the quarks. In the formula for Higgs plus multi-parton amplitudes, the massive Higgs boson is effectively described by two additional massless legs which do not appear in the Parke-Taylor factor. The latter also represents the first twistor-string/connected formula for form factors.

18 pages, 3 figures

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Cited by in corpus (28)

• Aspects of Scattering Amplitudes and Moduli Space Localization
• New BCJ representations for one-loop amplitudes in gauge theories and gravity
• A Three-Point Form Factor Through Five Loops
• On the Double Copy for Spinning Matter
• The Sudakov form factor at four loops in maximal super Yang-Mills theory
• Two-Loop SL(2) Form Factors and Maximal Transcendentality
• Labelled tree graphs, Feynman diagrams and disk integrals
• Non-planar form factors of generic local operators via on-shell unitarity and color-kinematics duality
• A note on connected formula for form factors
• From 4d Ambitwistor Strings to On Shell Diagrams and Back
• Full-color three-loop three-point form factors in N=4 SYM
• Understanding the Cancelation of Double Poles in the Pfaffian of CHY-formulism
• Form factor recursion relations at loop level
• Four dimensional ambitwistor strings and form factors of local and Wilson line operators
• On Positive Geometry and Scattering Forms for Matter Particles
• A String Deformation of the Parke-Taylor Factor
• A Monte Carlo Approach to the 4D Scattering Equations
• Space-time CFTs from the Riemann sphere
• Bootstrapping solutions of scattering equations
• CHY formulae in 4d
• Double copy for tree-level form factors. Part II. Generalizations and special topics
• Ambitwistor strings and reggeon amplitudes in N=4 SYM
• Multi-Regge kinematics and the scattering equations
• New relations for tree-level form factors and scattering amplitudes
• Analytic two-Loop four-point form factor of the stress-tensor supermultiplet in $\mathcal{N}=4$ SYM
• CHY Theory for Several Fields
• Color-factor symmetry and BCJ relations for QCD amplitudes
• On-shell Methods for Form Factors in N=4 SYM and Their Applications