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Measurement of the mass and width of the W boson

Research output: Contribution to journalJournal articlepeer-review

  • G. Abbiendi
  • C. Ainsley
  • P. F. Akesson
  • G. Alexander
  • G. Anagnostou
  • K. J. Anderson
  • S. Asai
  • D. Axen
  • I. Bailey
  • E. Barberio
  • T. Barillari
  • R. J. Barlow
  • R. J. Batley
  • P. Bechtle
  • T. Behnke
  • K. W. Bell
  • P. J. Bell
  • G. Bella
  • A. Bellerive
  • C. Benelli
  • S. Bethke
  • O. Biebel
  • O. Boeriu
  • P. Bock
  • M. Boutemeur
  • S. Braibant
  • R. M. Brown
  • H. J. Burckhart
  • S. Campana
  • P. Capiluppi
  • R. K. Carnegie
  • A. A. Carter
  • J. R. Carter
  • C. Y. Chang
  • D. C. Charlton
  • C. Ciocca
  • A. Csilling
  • M. Cuffiani
  • S. Dado
  • A. De Roeck
  • E. A. De Wolf
  • K. Desch
  • B. Dienes
  • J. Dubbert
  • E. Duchovni
  • G. Duckeck
  • I. P. Duerdoth
  • E. Etzion
  • F. Fabbri
  • P. Ferrari
  • OPAL Collaboration
<mark>Journal publication date</mark>02/2006
<mark>Journal</mark>European Physical Journal C: Particles and Fields
Issue number2
Number of pages29
Pages (from-to)307-335
Publication StatusPublished
<mark>Original language</mark>English


The mass and width of the W boson are measured using e(+)e(-) -> W+W- events from the data sample collected by the OPAL experiment at LEP at centre-of-mass energies between 170 GeV and 209 GeV. The mass (m(W)) and width (Gamma(W)) are determined using direct reconstruction of the kinematics of W+W- -> q (q) over bar lfv and W+W- -> q (q) over barq (q) over bar events. When combined with previous OPAL measurements using W+W- -> lvlv events and the dependence on m(W) of the WW production cross-section at threshold, the results are determined to be

m(W) = 80.415 +/- 0.042 +/- 0.030 +/- 0.009 GeV

Gamma(W) = 1.996 +/- 0.096 +/- 0.102 +/- 0.003 GeV

where the first error is statistical, the second systematic and the third due to uncertainties in the value of the LEP beam energy. By measuring m(W) in the q (q) over barq (q) over bar channel using several different determinations of the direction of jets with differing sensitivities to soft particles, a limit is also obtained on possible final-state interactions due to colour reconnection effects in W+W- -> q (q) over barq (q) over bar events. The consistency of the results for the W mass and width with those inferred from other electroweak parameters provides an important test of the Standard Model of electroweak interactions.