Studying the origin of a newZ′with polarized beams at future colliders

Motivated by recent technical progress in the acceleration and storage of polarized proton beams which would make feasible the measurement of spin-dependent observables at the energies of future colliders, we analyze forward-backward and spin asymmetries in the production of a new neutral gauge boson of ${\mathrm{E}}_6$ or left-right origin. These asymmetries could be used to probe the couplings of this new object, allowing us to distinguish among the various possible models.