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Published December 25, 1989 | Version Published
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Measurement of Z Decays into Lepton Pairs

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Abstract

We present measurements by the Mark II experiment of the ratios of the leptonic partial widths of the Z boson to the hadronic partial width. The results are Γ_(ee)/Γ_(had)=0.037_(-0.012^()+0.016),Γ_(µµ)/Γ_(had)=0.053-_(0.015)^(+0.020), and Γ_(ττ)/Γ_(had)=0.066_(-0.017)^(+0.021), in good agreement with the standard-model prediction of 0.048. From the average leptonic width result, Γ_(ll)/Γ_(had)=0.053_(-0.009)^(+0.010), we derive Γ_(had)=1.56_(-0.24)^(+0.28) GeV. We find for the vector coupling constants of the tau and muon v_τ^2=0.31±0.31_(-0.30)^(+0.43) and v_μ^2=0.05±0.30_(-0.23)^(+0.34).

Additional Information

© 1989 The American Physical Society. Received 24 October 1989; published in the issue dated 25 December 1989. One of us (M. Kuhlen) wishes to acknowledge the Alexander von Humboldt Foundation for its support. This work was funded in part by Department of Energy, Contracts No. DE-AC03-81-ER40050 (California Institute of Technology), No. DE-AM03-76SF00010 (University of California, Santa Cruz), No. DE-AC02-86ER40253 (University of Colorado), No. DE-AC03-83ER40103 (University of Hawaii), No. DE-AC02-84ER40125 (Indiana University), No. DE-AC03- 76SF00098 (LBL), No. DE-AC02-76ER01112 (University of Michigan), and No. DE-AC03-76SF00515(SLAC), and by the National Science Foundation (Johns Hopkins University).

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Identifiers

Eprint ID
31412
Resolver ID
CaltechAUTHORS:20120510-114415016

Funding

Alexander von Humboldt Foundation
Department of Energy (DOE)
DE-AC03-81-ER40050
Department of Energy (DOE)
DE-AM03-76SF00010
Department of Energy (DOE)
DE-AC02-86ER40253
Department of Energy (DOE)
DE-AC03-83ER40103
Department of Energy (DOE)
DE-AC02-84ER40125
Department of Energy (DOE)
DE-AC03-76SF00098
Department of Energy (DOE)
DE-AC02-76ER01112
Department of Energy (DOE)
DE-AC03-76SF00515
NSF

Dates

Created
2012-05-11
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Updated
2021-11-09
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