Constructing multiloop scattering amplitudes with manifest singularity structure

The infrared exponentiation properties of dimensionally regularized multiloop scattering amplitudes are typically hidden at the level of the integrand, materializing only after integral evaluation. We address this longstanding problem by introducing an appropriate integral basis which is simultaneously finite and uniform weight. As an example, we cast the integrand for the QCD corrections to the two-loop massless quark electromagnetic form factor into a form where it is manifest that the epsilon(-4) and epsilon(-3) pole terms arise from the epsilon expansion of the square of our one-loop master integral.