On the Coulomb Effects on the W Line Shape at LEP2

Abstract

One of the most powerful methods for obtaining a precision measurement of M_W at LEP2 is from direct reconstruction of the invariant mass distribution of W bosons produced in e+e- --> W+W-. We investigate the effects on the W line shape, and in particular on the average invariant mass, of phase-space and first-order Coulomb corrections. The latter are shown to have a non-negligible effect on the reconstructed mass, inducing shifts of order -20 MeV at collision energies above threshold, compared to the Born approximation cross section. The sign and magnitude of the effect can be understood in a simple model calculation in which one of the W bosons is assumed to be stable.

11 pages + 4 uuencoded postscript figures. Figures 1 and 2 were incorrect in the original submission and have now been corrected

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• On Colour Rearrangement in Hadronic W${}^{+}$W${}^{-}$ Events
• How suppressed are the radiative interference effects in heavy unstable particle production?
• Does the W Mass Reconstruction Survive QCD Effects?
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Cited by in corpus (8)

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• Precision Physics at LEP
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• Higher-order Coulomb Corrections to the Threshold e+ e- --> W+ W- Cross Section
• Final-State Interactions in e^+e^- -> t\bar{t} -> b l^+ ν\bar{b} W^- Near Top Quark Threshold
• Dirac prescription from BRST symmetry in FRW space-time
• NLO QCD corrections to the production of off--shell WW pairs at $e^{+}{e}^{-}$ colliders
• WW Physics at LEP2