On the choice of beam polarization in e+e- → ZZ/Zγ and anomalous triple gauge-boson couplings

The anomalous trilinear gauge couplings of Z and. are studied in e(+)e(-) -> ZZ/Z gamma with longitudinal beam polarizations using a complete set of polarization asymmetries for the Z boson. We quantify the goodness of the beam polarization in terms of the likelihood and find the best choice of e(-) and e(+) polarizations to be (+0.16, -0.16), (+0.09, -0.10) and (+0.12, -0.12) for ZZ, Z gamma and combined processes, respectively. Simultaneous limits on anomalous couplings are obtained for these choices of beam polarizations using Markov-Chain-Monte-Carlo (MCMC) for an e(+) (e)- collider running atv root s = 500 GeV and L = 100 fb(-1). We find the simultaneous limits for these beam polarizations to be comparable with each other and also comparable with the unpolarized beam case.