I present a class of functions unifying all singular limits for the emission of soft or collinear gluons in gauge-theory amplitudes at any order in perturbation theory. Each function is a generalization of the antenna functions of previous works. The helicity-summed interferences of these functions are thereby also generalizations to higher orders of the Catani-Seymour dipole factorization function.

• Received 3 February 2003

DOI:https://doi.org/10.1103/PhysRevLett.91.061602