Optimal estimation of dimension-8 neutral triple gauge couplings at the e+e− colliders

Abstract

Abstract We investigate the measurement of non-standard ZZV (V = γ, Z) couplings through Z-boson pair production at the e+e− colliders. We adopt the Standard Model Effective Field Theory (SMEFT) approach to study these anomalous neutral triple gauge couplings. There are one CP-conserving and three CP-violating dim-8 SMEFT operators that contribute to ZZV couplings. Using the optimal observable technique, the sensitivity of these new physics couplings has been estimated and compared with the latest experimental limits on dim-8 couplings at the LHC at CERN. The effect of beam polarization and correlations among CP-violating ZZV couplings are discussed. The comparison of statistical limits of new physics couplings between optimal observable technique and contemporary cut-based analysis has also been studied in detail.