Study of spin and decay-plane correlations of W bosons in the e(+) e(-)-> W+W- process at LEP

Data collected at LEP at centre-of-mass energies √s = 189-209 GeV are used to study correlations of the spin of W bosons using e + e - → W + W - →lνqqevents. Spin correlations are favoured by data, and found to agree with the Standard Model predictions. In addition, correlations between the W-boson decay planes are studied in e + e - → W + W - →lνqq and ee + e - → W + W - →qqqqevents. Decay-plane correlations are measured to be consistent with the Standard Model predictions.