Wilson Lines and Boundary Operators of BCFW Shifts

Abstract

Boundary operators are gauge invariant operators whose form factors correspond to boundary contributions of BCFW shifts. In gauge theory, the boundary operators contain infinite series, which are constrained by gauge symmetry. We compute the boundary operators of all possible BCFW shifts in Yang-Mills theory and QCD, and show that the infinite series can be elegantly organized into Wilson lines, which are natural building blocks for non-local gauge invariant operators. We comment on their connection to jet functions and gauge invariant off-shell amplitudes. We also verify our results by studying various BCFW shifts of four and five-point amplitudes.

28 pages, 5 figures, improve the writing and correct some typos

References in corpus (7)

• Toward a NNLO calculation of the B-->X_s+gamma decay rate with a cut on photon energy: II. Two-loop result for the jet function
• Multi-gluon helicity amplitudes with one off-shell leg within high energy factorization
• Structure of the MHV-rules Lagrangian
• Wilson lines and gauge invariant off-shell amplitudes
• Determination of Boundary Contributions in Recursion Relation
• Recursion relations for multi-gluon off-shell amplitudes on the light-front and Wilson lines
• Wilson lines in the MHV action