| 1. |
- Schael, S, et al.
(author)
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Precision electroweak measurements on the Z resonance
- 2006
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In: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Research review (peer-reviewed)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 2. |
- Abreau, P, et al.
(author)
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Photon events with missing energy at root s=183 to 189 GeV
- 2000
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In: EUROPEAN PHYSICAL JOURNAL C. - : SPRINGER-VERLAG. - 1434-6044. ; 17:1, s. 53-65
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Journal article (peer-reviewed)abstract
- The production of single photons has been studied in the reaction e(+)e(-) --> gamma +invisible particles at centre-of-mass energies of 183 GeV and 189 GeV. A previously published analysis of events with multiphoton final states accompanied by missing ene
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| 3. |
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| 4. |
- Abreu, P, et al.
(author)
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A measurement of the Tau topological branching ratios
- 2001
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In: EUROPEAN PHYSICAL JOURNAL C. - : SPRINGER-VERLAG. - 1434-6044. ; 20:4, s. 617-637
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Journal article (peer-reviewed)abstract
- Using data collected in the DELPHI detector at LEP-1, measurements of the inclusive T branching ratios for decay modes containing one, three, or five charged particles have been performed, giving the following results: B-1 equivalent to B T- (particle)(-)
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| 5. |
- Abreu, P, et al.
(author)
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A precise measurement of the tau polarisation at LEP-1
- 2000
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In: EUROPEAN PHYSICAL JOURNAL C. - : SPRINGER VERLAG. - 1434-6044. ; 14:4, s. 585-611
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Journal article (peer-reviewed)abstract
- The tau polarisation has been studied with the e(+)e(-) --> tau(+)tau(-) data collected by the DELPHI detector at LEP in 1993, 1994 and 1995 around the Z resonance firstly through the exclusive decay channels ev (v) over bar, mu v (v) over bar, pi v, rho
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| 6. |
- Abreu, P, et al.
(author)
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A study of the Lorentz structure in tau decays
- 2000
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In: EUROPEAN PHYSICAL JOURNAL C. - : SPRINGER-VERLAG. - 1434-6044. ; 16:2, s. 229-252
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Journal article (peer-reviewed)abstract
- This paper describes a measurement of the Michel parameters, eta, rho, xi, xi delta, and the average v(tau) helicity, h(nu tau), in tau lepton decays together with the first measurement of the tensor coupling in the weak charged current. The tau(+)tau(-)
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| 7. |
- Abreu, P, et al.
(author)
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Consistent measurements of alpha(s) from precise oriented event shape distributions
- 2000
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In: EUROPEAN PHYSICAL JOURNAL C. - : SPRINGER VERLAG. - 1434-6044. ; 14:4, s. 557-584
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Journal article (peer-reviewed)abstract
- An updated analysis using about 1.5 million events recorded at root s = M-Z with the DELPHI detector in 1994 is presented. Eighteen infrared and collinear safe event shape observables are measured as a function of the polar angle of the thrust. axis. The
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| 8. |
- Abreu, P, et al.
(author)
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Cross-sections and leptonic forward-backward asymmetries from the Z(0) running of LEP
- 2000
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In: EUROPEAN PHYSICAL JOURNAL C. - : SPRINGER-VERLAG. - 1434-6044. ; 16:3, s. 371-405
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Journal article (peer-reviewed)abstract
- During 1993 and 1995 LEP was run at 3 energies near the Z(0) peak in order to give improved measurements of the mass and width of the resonance. During 1994, LEP operated only at the Z(0) peak. In total DELPHI accumulated data corresponding to an integrat
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| 9. |
- Abreu, P, et al.
(author)
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Determination of P(c -> D*(+)) and BR(c -> l(+)) at LEP 1
- 2000
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In: EUROPEAN PHYSICAL JOURNAL C. - : SPRINGER VERLAG. - 1434-6044. ; 12:2, s. 209-224
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Journal article (peer-reviewed)abstract
- The probability P(c --> D*(+)) that a charm quark fragments into a D*+ meson and the c --> l(+) semileptonic branching fraction were measured in Z(0) decay into c (c) over bar events. From the analysis of 3.5 Million Z(0) events collected from 1992 to 199
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| 10. |
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