Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
<mark>Journal publication date</mark> | 30/12/1999 |
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<mark>Journal</mark> | Physics Letters B |
Issue number | 2-3 |
Volume | 471 |
Number of pages | 15 |
Pages (from-to) | 293-307 |
Publication Status | Published |
<mark>Original language</mark> | English |
A study of W+W- events accompanied by hard photon radiation produced in e(+)e(-) collisions at LEP is presented. Events consistent with two on-shell W-bosons and an isolated photon are selected from 183 pb(-1) of data recorded at root s = 189 GeV. From these data, 17 W+W- gamma candidates are selected with photon energy greater than 10 GeV, consistent with the Standard Model expectation. These events are used to measure the e(+)e(-) --> W+W- gamma cross-section within a set of geometric and kinematic cuts, <(sigma)over cap>(WW gamma) = 136 +/- 37 +/- 8 fb, where the first error is statistical and the second systematic. The photon energy spectrum is used to set the first direct, albeit weak, limits on possible anomalous contributions to the W+W- gamma gamma and W+W- gamma Z(0) vertices:
0.070GeV(-2) < a(0)/Lambda(2) < 0.070 GeV-2,
0.13GeV(-2) < a(c)/Lambda(2) < 0.19 GeV-2,
0.61GeV(-2) < a(n)/Lambda(2) < 0.57 GeV-2,
where Lambda represents the energy scale for new physics. (C) 1999 Published by Elsevier Science B.V. All rights reserved.