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Measurement of Z Decays into Lepton Pairs

Abrams, G. S. and Barish, B. C. and Hawkes, C. M. and Kuhlen, M. and McKenna, J. A. and Milliken, B. D. and Peck, C. and Porter, F. C. and Soderstrom, E. and Stroynowski, R. and Weir, A. J. and Wicklund, E. and Wu, D. Y. and Weinstein, Alan J. (1989) Measurement of Z Decays into Lepton Pairs. Physical Review Letters, 63 (26). pp. 2780-2783. ISSN 0031-9007. doi:10.1103/PhysRevLett.63.2780.

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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).

Item Type:Article
Related URLs:
URLURL TypeDescription
Porter, F. C.0000-0003-1948-8889
Weinstein, Alan J.0000-0002-0928-6784
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).
Funding AgencyGrant Number
Alexander von Humboldt FoundationUNSPECIFIED
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
Issue or Number:26
Classification Code:PACS: 13.38.+c, 12.15.Ji
Record Number:CaltechAUTHORS:20120510-114415016
Persistent URL:
Official Citation:Measurement of Z decays into lepton pairs G. S. Abrams et al. pp. 2780-2783
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:31412
Deposited By: Ruth Sustaita
Deposited On:11 May 2012 19:45
Last Modified:09 Nov 2021 19:52

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