M. Acciarri et al., Production of single W bosons at root s=189 GeV and measurement of WW gamma gauge couplings, PHYS LETT B, 487(3-4), 2000, pp. 229-240
Single W boson production in electron-positron collisions is studied with t
he L3 detector at LEP. The data sample collected at a centre-of-mass energy
of root s = 188.7 GeV corresponds to an integrated luminosity of 176.4 pb(
-1). Events with a single energetic lepton or two acoplanar hadronic jets a
re selected. Within phase-space cuts, the total cross-section is measured t
o be 0.53 +/- 0.12 +/- 0.03 pb, consistent with the Standard Model expectat
ion. Including our single W boson results obtained at lower root s, the WW
gamma gauge couplings kappa(gamma) and lambda(gamma) are determined to be k
appa(gamma) = 0.93 +/- 0.16 +/- 0.09 and lambda(gamma) = -0.31(-0.19)(+0.68
) +/- 0.13. (C) 2000 Elsevier Science B.V. All rights reserved.