Z -boson polarization as a model-discrimination analyzer

Determining the spin of any new particle is critical in identifying the true theory among various extensions of the standard model (SM). The degree of Z-boson polarization in any two-body decay process A → BZ is sensitive to the spin assignments of two new particles A and B. Considering all possible spin-0, 1/2, and 1 combinations in a renormalizable field theory, we demonstrate that Z-boson polarization can indeed play a role of a decisive and universal analyzer in distinguishing the different spin assignments.