Determination of the number of light neutrino species

D. DeCamp, B. Deschizeaux, J. P. Lees, M. N. Minard, J. M. Crespo, M. Delfino, E. Fernandez, M. Martinez, R. Miquel, M. L. Mir, S. Orteu, A. Pacheco, J. A. Perlas, E. Tubau, M. G. Catanesi, M. de Palma, A. Farilla, G. Iaselli, G. Maggi, A. MastrogiacomoS. Natali, S. Nuzzo, A. Ranieri, G. Raso, F. Romano, F. Ruggieri, G. Selvaggi, L. Silvestris, P. Tempesta, G. Zito, Y. Chen, D. Huang, J. Lin, T. Ruan, T. Wang, W. Wu, Y. Xie, D. Xu, R. Xu, J. Zhang, W. Zhao, H. Albrecht, F. Bird, E. Blucher, T. Charity, H. Drevermann, Ll Garrido, C. Grab, R. Hagelberg, S. Haywood, B. Jost, M. Kasemann, G. Kellner, J. Knobloch, A. Lacourt, I. Lehraus, T. Lohse, D. Lüke, A. Marchioro, P. Mato, J. May, V. Mertens, A. Minten, A. Miotto, P. Palazzi, M. Pepe-Altarelli, F. Ranjard, J. Richstein, A. Roth, J. Rothberg, H. Rotscheidt, W. von Rüden, D. Schlatter, R. St.Denis, M. Takashima, M. Talby, H. Taureg, W. Tejessy, H. Wachsmuth, S. Wheeler, W. Wiedenmann, W. Witzeling, J. Wotschack, Z. Ajaltouni, M. Bardadin-Otwinowska, A. Falvard, P. Gay, P. Henrard, J. Jousset, B. Michel, J. C. Montret, D. Pallin, P. Perret, J. Prat, J. Proriol, F. Prulhière, H. Bertelsen, F. Hansen, J. R. Hansen, J. D. Hansen

Research output: Contribution to journalArticleResearchpeer-review

250 Citations (Scopus)


The cross-section for e+e- → hadrons in the vicinity of the Z boson peak has been measured with the ALEPH detector at the CERN Large Electron Positron collider, LEP. Measurements of the Z mass, Mz = (91.174±0.070) GeV, the Z width Γz=(2.68±0.15) GeV, and of the peak hadronic cross-section, σhadpeak=(29.3±1.2) nb, are presented. With the constraints of the standard electroweak model, the number of light neutrino species is found to be Nv=3.27±0.30. this results rules out of the possibility of a fourth type of light neutrino at 98% CL. © 1989.
Original languageEnglish
Pages (from-to)519-529
JournalPhysics Letters B
Issue number4
Publication statusPublished - 16 Nov 1989


Dive into the research topics of 'Determination of the number of light neutrino species'. Together they form a unique fingerprint.

Cite this