New physics in e⁺e⁻→Zγ with polarized beams

Abstract

We present a complete description of angular distributions in the presence of new interactions for the process e⁺e⁻→Zγ with polarized beams at future linear colliders, by considering the most general form-factors allowed by gauge invariance. We include the possibility of CP violation, and classify the couplings according to their CP properties. Chirality conserving and chirality violating couplings give rise to distinct dependence on beam polarization. We present a comprehensive discussion including both types of couplings and provide a detailed comparison of the effects due to each. We discuss some selected asymmetries which would enable isolating effects of the CP-violating form-factors. We also present sensitivities on the corresponding couplings achievable at a future linear collider with realistic polarization and luminosity.