More extensive and precise results are reported on the parameters of Z decay. On the basis of 20 000 Z decays collected with the ALEPH detector at LEP we find Mz=91.182±0.026 (exp.) ±0.030 (beam) GeV, Γz=2.541±0.056 GeV and σhad0=41.4±0.8 nb. The partial widths for the hadronic and leptonic channels are Γhad=1804±44 MeV, Γe+e−=82.1±3.4 MeV, Γμ+μ−=87.9±6.0 MeV and Γτ+τ−=86.1±5.6 MeV, in good agreement with the standard model. On the basis of the average leptonic width Γℓ+ℓ−=83.9±2.2 MeV, the effective weak mixing angle is found to be sin2θw(Mz)=0.231±0.008. Usin g the partial widths calculated in the standard model, the number of light neutrino families is Nν=3.01±0.15 (exp.)±0.05 (theor.).
A precise determination of the number of families with light neutrinos and of the Z boson partial widths / D. Decamp, B. Deschizeaux, J. Lees, M. Minard, J. Crespo, M. Delfino, E. Fernandez, M. Martinez, R. Miquel, L. Mir, S. Orteu, A. Pacheco, J. Perlas, E. Tubau, M. Catanesi, M. De Palma, A. Farilla, G. Iaselli, G. Maggi, S. Natali, S. Nuzzo, A. Ranieri, G. Raso, F. Romano, F. Ruggieri, G. Selvaggi, L. Silvestris, P. Tempesta, G. Zito, H. Hu, D. Huang, J. Lin, T. Ruan, T. Wang, W. Wu, Y. Xie, D. Xu, R. Xu, J. Zhang, W. Zhao, H. Albrecht, W. Atwood, F. Bird, E. Blucher, T. Burnett, T. Charity, H. Drevermann, L. Garrido, C. Grab, R. Hagelberg, S. Haywood, B. Jost, M. Kasemann, G. Kellner, J. Knobloch, A. Lacourt, I. Lehraus, T. Lohse, D. Luke, A. Marchioro, P. Mato, J. May, A. Minten, A. Miotto, P. Palazzi, M. Pepealtarelli, F. Ranjard, A. Roth, J. Rothberg, H. Rotscheidt, W. Vonruden, R. Stdenis, D. Schlatter, M. Takashima, M. Talby, H. Taureg, W. Tejessy, H. Wachsmuth, S. Wheeler, W. Wiedenmann, W. Witzeling, J. Wotschack, Z. Ajaltouni, M. Bardadinotwinowska, A. Falvard, P. Gay, P. Henrard, J. Jousset, B. Michel, J. Montret, D. Pallin, P. Perret, J. Proriol, F. Prulhiere, J. Hansen, J. Hansen, P. Hansen, R. Mollerud, G. Petersen, E. Simopoulou, A. Vayaki, J. Badier, A. Blondel, G. Bonneaud, J. Bourotte, F. Braems, J. Brient, M. Ciocci, G. Fouque, R. Guirlet, A. Rouge, M. Rumpf, R. Tanaka, H. Videau, I. Videau, D. Candlin, A. Conti, G. Parrini, M. Corden, C. Georgiopoulos, J. Goldman, M. Ikeda, J. Lannutti, D. Levinthal, M. Mermikides, L. Sawyer, G. Stimpfl, A. Antonelli, R. Baldini, G. Bencivenni, G. Bologna, F. Bossi, P. Campana, G. Capon, V. Chiarella, G. Deninno, B. Dettorrepiazzoli, G. Felici, P. Laurelli, G. Mannocchi, F. Murtas, G. Murtas, G. Nicoletti, P. Picchi, P. Zografou, B. Altoon, O. Boyle, A. Halley, I. Tenhave, J. Hearns, I. Hughes, J. Lynch, W. Morton, C. Raine, J. Scarr, K. Smith, A. Thompson, B. Brandl, O. Braun, R. Geiges, C. Geweniger, P. Hanke, V. Hepp, E. Kluge, Y. Maumary, M. Panter, A. Putzer, B. Rensch, A. Stahl, K. Tittel, M. Wunsch, A. Belk, R. Beuselinck, D. Binnie, W. Cameron, M. Cattaneo, P. Dornan, S. Dugeay, R. Forty, A. Greene, J. Hassard, S. Patton, J. Sedgbeer, G. Taylor, I. Tomalin, A. Wright, P. Girtler, D. Kuhn, G. Rudolph, C. Bowdery, T. Brodbeck, A. Finch, F. Foster, G. Hughes, N. Keemer, M. Nuttall, B. Rowlingson, T. Sloan, S. Snow, T. Barczewski, L. Bauerdick, K. Kleinknecht, B. Renk, S. Roehn, H. Sander, M. Schmelling, F. Steeg, J. Albanese, J. Aubert, C. Benchouk, A. Bonissent, D. Courvoisier, F. Etienne, E. Matsinos, S. Papalexiou, P. Payre, B. Pietrzyk, Z. Qian, W. Blum, P. Cattaneo, G. Cowan, B. Dehning, H. Dietl, M. Fernandezbosman, D. Hauff, A. Jahn, E. Lange, G. Lutjens, G. Lutz, W. Manner, H. Moser, Y. Pan, R. Richter, A. Schwarz, R. Settles, U. Stiegler, U. Stierlin, J. Thomas, G. Waltermann, V. Bertin, G. Debouard, J. Boucrot, O. Callot, X. Chen, A. Cordier, M. Davier, G. Ganis, J. Grivaz, P. Heusse, P. Janot, V. Journe, D. Kim, J. Lefrancois, A. Lutz, J. Veillet, F. Zomer, S. Amendolia, G. Bagliesi, G. Batignani, L. Bosisio, U. Bottigli, C. Bradaschia, I. Ferrante, F. Fidecaro, L. Foa, E. Focardi, F. Forti, A. Giassi, M. Giorgi, F. Ligabue, A. Lusiani, E. Mannelli, P. Marrocchesi, A. Messineo, F. Palla, G. Sanguinetti, S. Scapellato, J. Steinberger, R. Tenchini, G. Tonelli, G. Triggiani, J. Carter, M. Green, P. March, T. Medcalf, M. Saich, J. Strong, R. Thomas, T. Wildish, D. Botterill, R. Clifft, T. Edgecock, M. Edwards, S. Fisher, J. Harvey, T. Jones, P. Norton, D. Salmon, J. Thompson, E. Aubourg, B. Blochdevaux, P. Colas, C. Klopfenstein, E. Lancon, E. Locci, S. Loucatos, L. Mirabito, E. Monnier, P. Perez, F. Perrier, J. Rander, J. Renardy, A. Roussarie, J. Schuller, J. Ashman, C. Booth, F. Combley, M. Dinsdale, J. Martin, D. Parker, L. Thompson, S. Brandt, H. Burkhardt, C. Grupen, H. Meinhard, E. Neugebauer, U. Schafer, H. Seywerd, B. Gobbo, F. Liello, E. Milotti, F. Ragusa, L. Rolandi, L. Bellantoni, J. Boudreau, D. Cinabro, J. Conway, D. Cowen, Z. Feng, J. Harton, J. Hilgart, R. Jared, R. Johnson, B. Leclaire, Y. Pan, T. Parker, J. Pater, Y. Saadi, V. Sharma, J. Wear, F. Weber, S. Wu, S. Xue, G. Zobernig. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - 235:3/4(1990), pp. 399-411.
A precise determination of the number of families with light neutrinos and of the Z boson partial widths
F. Ragusa;
1990
Abstract
More extensive and precise results are reported on the parameters of Z decay. On the basis of 20 000 Z decays collected with the ALEPH detector at LEP we find Mz=91.182±0.026 (exp.) ±0.030 (beam) GeV, Γz=2.541±0.056 GeV and σhad0=41.4±0.8 nb. The partial widths for the hadronic and leptonic channels are Γhad=1804±44 MeV, Γe+e−=82.1±3.4 MeV, Γμ+μ−=87.9±6.0 MeV and Γτ+τ−=86.1±5.6 MeV, in good agreement with the standard model. On the basis of the average leptonic width Γℓ+ℓ−=83.9±2.2 MeV, the effective weak mixing angle is found to be sin2θw(Mz)=0.231±0.008. Usin g the partial widths calculated in the standard model, the number of light neutrino families is Nν=3.01±0.15 (exp.)±0.05 (theor.).
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