  In QCD, the amplitude for multiple soft gluon emissions has been shown to
exhibit a form of coherence, wherein one-loop corrections are rendered IR
finite by the transverse momentum of the real emissions. Using a sequence of
soft-collinear effective theories (SCET) with Glauber operators, we present a
compact and elegant derivation of this property. Our derivation highlights an
important role played by the Lipatov vertex. The EFT approach provides
increased physical intuition and, for the first time, a clear road map for how
this result can be extended to higher loop orders.

High Energy Physics - Phenomenology