@article{d89caa5ccb15435aaf6533620ccffff9,
title = "An improved measurement of Rb using a double tagging method",
abstract = "This paper describes an update of the double tagging measurement of the fraction, Rb, of Z0 → b{\=b} events in hadronic Z0 decays, with statistics improved by including the data collected in 1994. The presence of electrons or muons from semileptonic decays of bottom hadrons and the detection of bottom hadron decay vertices were used together to obtain an event sample enriched in Z0 → b{\=b} decays. The efficiency of the b{\=b} event tagging was obtained from the data by comparing the numbers of events having a bottom signature in either one or both thrust hemispheres. Efficiency correlations between opposite event hemispheres are small (< 0.5%) and well understood through comparisons between the real and simulated data samples. A value of Rb = 0.2175 ± 0.0014 ± 0.0017 was obtained, where the first error is statistical and the second systematic. The uncertainty on the decay width Γ(Z0 → c{\=c}) is not included in these errors. The result depends on Rc as follows: ΔRb/Rb = -0.084 ΔRc/Rc, where ΔRc is the deviation of Rc from the value 0.172 predicted by the Standard Model.",
author = "{The OPAL Collaboration} and K. Ackerstaff and G. Alexander and J. Allison and N. Altekamp and K. Ametewee and Anderson, {K. J.} and S. Anderson and S. Arcelli and S. Asai and D. Axen and G. Azuelos and Ball, {A. H.} and E. Barberio and Barlow, {R. J.} and R. Bartoldus and Batley, {J. R.} and J. Bechtluft and C. Beeston and T. Behnke and Bell, {A. N.} and Bell, {K. W.} and G. Bella and S. Bentvelsen and P. Berlich and S. Bethke and O. Biebel and A. Biguzzi and V. Blobel and Bloodworth, {I. J.} and Bloomer, {J. E.} and M. Bobinski and P. Bock and Bosch, {H. M.} and M. Boutemeur and Bouwens, {B. T.} and S. Braibant and Brown, {R. M.} and Burckhart, {H. J.} and C. Burgard and R. B{\"u}rgin and P. Capiluppi and Carnegie, {R. K.} and Carter, {A. A.} and Carter, {J. R.} and Chang, {C. Y.} and Charlton, {D. G.} and D. Chrisman and Clarke, {P. E.L.} and I. Cohen and R. Folman",
note = "Funding Information: Acknowledgements. We particularly wish to thank the SL Division for the efficient operation of the LEP accelerator and for their continuing close cooperation with our experimental group. In addition to the support staff at our own institutions we are pleased to acknowledge the Department of Energy, USA, National Science Foundation, USA, Particle Physics and Astronomy Research Council, UK, Natural Sciences and Engineering Research Council, Canada, Israel Science Foundation, administered by the Israel Academy of Science and Humanities, Minerva Gesellschaft, Japanese Ministry of Education, Science and Culture (the Monbusho) and a grant under the Monbusho International Science Research Program, German Israeli Bi-national Science Foundation (GIF), Direction des Sciences de la Mati{\`e}re du Commissariat {\`a} l{\textquoteright}Energie Atomique, France, Bundesministerium f{\"u}r Bildung, Wissenschaft, Forschung und Technologie, Germany, National Research Council of Canada, Hungarian Foundation for Scientific Research, OTKA T-016660, and OTKA F-015089.",
year = "1997",
month = mar,
day = "1",
doi = "10.1007/s002880050366",
language = "English",
volume = "74",
pages = "1--17",
journal = "Zeitschrift fur Physik C-Particles and Fields",
issn = "0170-9739",
publisher = "Springer New York",
number = "1",
}