The inclusive branching ratios of the τ lepton to one, three and five charged particle final states are measured from data collected with the OPAL detector at LEP. The data sample consists of 12707e+e- → τ+τ- candidate events and has an estimated background of 1.9%. The branching ratios are obtained from a simultaneous fit to the data which gives B1 = 84.48 ± 0.27 (stat) ±0.23 (sys)%, B3 = 15.26±0.26±0.22% and B5 = 0.26±0.06±0.05% respectively where B1 + B3 + B5 is constrained to equal one. The inclusive one-prong branching ratio is found to be significantly lower than the 1990 Particle Data Group world average while the branching ratio to three charged particles is correspondingly higher. The five-prong branching ratio is in agreement with the world average measurement.

Original languageEnglish
Pages (from-to)373-385
Number of pages13
JournalPhysics Letters B
Issue number3-4
StatePublished - 27 Aug 1992


FundersFunder number
American Israeli Bi-national Science Foundation
Direction des Sciences de la Mati6re du Commissariat h l'Energie Atomique
Israeli Ministry of Science
Junta Nacional de Investigag~o Cient~fica e Tecnol6gica
Minerva Gesellschaft
National Science Foundation
U.S. Department of Energy
Alfred P. Sloan Foundation
Natural Sciences and Engineering Research Council of Canada
National Research Council Canada
Ministry of Education, Culture, Sports, Science and Technology
Bundesministerium für Forschung und Technologie


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