In the Standard Model (SM), fundamental particles acquire their masses through the Higgs mechanism. These resulting Goldstone bosons are absorbed into the W and Z bosons and become their longitudinal components, consequently making these gauge bosons massive. Thus, studying the longitudinal components of the W and Z bosons allows the probing of one of the cornerstones of the SM theory.

Vector boson scattering (VBS) events are often used to study longitudinal-longitudinal vector boson interactions. However, VBS processes have low production cross sections and only in recent years all VBS processes were observed for the first time.

Instead, this talk focuses on a study of longitudinal-longitudinal WZ interactions using diboson WZ → ℓνℓℓ events. Additionally the considered events are constrained to have p_T^Z > 200 GeV to enhance the contribution of the s-channel production where the bosons directly interact as well as p_T^WZ<70 GeV to isolate leading-order like events that exhibit a radiation amplitude zero effect, reducing the contribution from doubly-transversely polarized events.

This phase space has a significantly increased fraction of direct longitudinal-longitudinal vector boson interactions, allowing for an important and unique test of the standard model and electroweak symmetry breaking.