  Measuring longitudinally polarized vector boson scattering in, e.g., the ZZ
channel is a promising way to investigate the unitarization scheme from the
Higgs and possible new physics beyond the Standard Model. However, at the LHC,
it demands the end of the HL-LHC lifetime luminosity, 3000/fb, and advanced
data analysis technique to reach the discovery threshold due to its small
production rates. Instead, there could be great potential for future colliders.
In this paper, we perform a Monte Carlo study and examine the projected
sensitivity of longitudinally polarized ZZ scattering at a TeV scale muon
collider. We conduct studies at 14 TeV and 6 TeV muon colliders respectively
and find that a 5 standard deviation discovery can be achieved at a 14 TeV muon
collider, with 3000/fb of data collected. While a 6 TeV muon collider can
already surpass HL-LHC, reaching 2 standard deviations with around 4000/fb of
data. The effect from lepton isolation and detector granularity is also
discussed, which may be more obvious at higher energy muon colliders, as the
leptons from longitudinally polarized Z decays tend to be closer.
