Acciarri, M (reprint author), IST NAZL FIS NUCL, VIA CELORIA 16, I-20133 MILAN, ITALY.
We report on the measurement of W-boson pair-production with the L3 detector at LEP at a centre-of-mass energy of 161.34 GeV. In a data sample corresponding to a total luminosity of II pb(-1), we select four-fermion events with high invariant masses of pairs of hadronic jets or leptons. Combining all final states, the measured total cross section for W-pair production is: sigma(ww) = 2.89(-0.70)(+0.81) (stat.) +/- 0.14 (syst.) pb. Within the Standard Model, this corresponds to a mass of the W boson of M-w = 80.80(-0.42)(+0.48) (exp.) +/- 0.03 (LEP) GeV. Limits on anomalous triple-vector-boson couplings are derived. (C) 1997 Published by Elsevier Science B.V.