Study of anomalous W-W+γ/Z couplings using polarizations and spin correlations in e-e+→W-W+ with polarized beams

We investigate the anomalous W - W + γ / Z couplings in e - e + → W - W + followed by semileptonic decay using a complete set of polarization and spin correlation observables of W boson with the longitudinally polarized beam. We consider a complete set of dimension-six operators affecting W - W + γ / Z vertex, which are S U ( 2 ) × U ( 1 ) gauge invariant. Some of the polarization and spin correlation asymmetries average out if the daughter of W + is not tagged and to overcome this we developed an artificial neural network and boosted decision trees to distinguish down-type jets from up-type jets. We obtain bounds on the anomalous couplings using MCMC analysis at s = 250 GeV with integrated luminosities of L ∈ { 100 fb - 1 , 250 fb - 1 , 1000 fb - 1 , 3000 fb - 1 } and different sets of systematic errors. We find that using spin-related observables along with cross section in the presence of initial beam polarization significantly improves the bounds on anomalous couplings compared to previous studies.