Gluon-gluon antenna functions from Higgs boson decay

Antenna functions describe the infrared singular behaviour of colour-ordered QCD matrix elements due to the emission of unresolved partons inside an antenna formed by two hard partons. In this Letter, we show that antenna functions for hard gluon-gluon pairs can be systematically derived from the effective Lagrangian describing Higgs boson decay into gluons, and compute the infrared structure of the colour-ordered Higgs boson decay matrix elements at NLO and NNLO.