Helicity Polarization Interference in Polarized Single- and Multiboson Production

After electroweak symmetry breaking, the W and Z bosons acquire masses and possess longitudinal polarizations in the on-shell limit. This is a radical departure from the physics of on-shell photons and gluons, and motivates many measurements and searchers at the Large Hadron Collider (LHC). Intriguingly, LHC data suggests that high-energy processes with resonant, helicity-polarized weak bosons are well described by an incoherent sum of polarized contributions. In other words, the quantum mechanical interference among intermediate polarization states in inclusive measurements is small. In this talk, we show that this can be understood from current conservation and kinematics, with high-energy W and Z bosons behaving like long-lived, asymptotic states that are distinguishable (in the quantum mechanical sense). The technical parts of the talk relate to how BRST cancellations are manifestly maintained despite working directly with intermediate, polarized bosons that are possibly (slightly) off shell.