I derive a class of functions unifying all singular limits for the emission of a given number of soft or collinear gluons in tree-level gauge-theory amplitudes. Each function is a generalization of the single-emission antenna function of my earlier paper. The helicity-summed squares of these functions are thus also generalizations to multiple singular emission of the Catani-Seymour dipole factorization function.

• Received 9 January 2003

DOI:https://doi.org/10.1103/PhysRevD.67.116003