Abstract.
The tau lepton lifetime has been measured with the \({\rm e}^ + {\rm e}^- \rightarrow {\rm\tau}^ + {\rm\tau}^-\) events collected by the DELPHI detector at LEP in the years 1991-1995. Three different methods have been exploited, using both one-prong and three-prong \(\tau\) decay channels. Two measurements have been made using events in which both taus decay to a single charged particle. Combining these measurements gave \(\tau_\tau \mbox{(1 prong)} = 291.8\pm 2.3_{\mathrm{stat}} \pm 1.5_{\mathrm{sys}} \mathrm{fs}\). A third measurement using taus which decayed to three charged particles yielded \(\tau_\tau \mbox{(3 prong)} = 288.6\pm 2.4_{\mathrm{stat}} \pm 1.3_{\mathrm{sys}} \mathrm{fs}. \) These were combined with previous DELPHI results to measure the tau lifetime, using the full LEP1 data sample, to be \(\tau_\tau = 290.9\pm 1.4_{\mathrm{stat}} \pm 1.0_{\mathrm{sys}} \mathrm{fs}\).
Similar content being viewed by others
References
Y.S. Tsai, Phys. Rev. D 4, 2821 (1971); H.B. Thacker and J.J. Sakurai, Phys. Lett. B 36, 103 (1971)
P. Abreu et al. , DELPHI Collaboration, Phys. Lett. B 365, 448 (1996)
N. Bingefors et al. , Nucl. Instr. and Meth. A 328, 447 (1993); V. Chabaud et al. , Nucl. Instr. and Meth. A 368, 314 (1996)
P. Abreu et al. , DELPHI Collaboration, Phys. Lett. B 302, 356 (1993)
K. Hagiwara Phys. Rev. D 66, 010001 (2002)
S. Jadach, B.F.L. Ward and Z. Was, Comput. Phys. Commun. 79, 503 (1994)
S. Jadach et al. , Comput. Phys. Commun. 76, 361 (1993)
J.E. Campagne and R. Zitoun, Zeit. Phys. C 43, 469 (1989)
F.A. Berends, R. Kleiss and W. Hollik, Nucl. Phys. B 304, 712 (1988)
S. Jadach, W. Placzek and B.F.L. Ward, Phys. Lett. B 390, 298 (1997)
P. Abreu et al. , DELPHI Collaboration, Zeit. Phys. C 73, 11 (1996)
F.A. Berends, P.H. Daverveldt and R. Kleiss, Phys. Lett. B 148, 489 (1984); Comput. Phys. Commun. 40, 271 (1986)
T. Alderweireld et al. , CERN Report CERN-2000-009, 219 (2000)
P. Abreu et al. , DELPHI Collaboration, Nucl. Instr. and Meth. A 378, 57 (1996)
P. Aarnio et al. , DELPHI Collaboration, Nucl. Instr. and Meth. A 303, 233 (1991)
P. Abreu et al. , DELPHI Collaboration, Eur. Phys. J. C 10, 415 (1999)
P. Abreu et al. , DELPHI Collaboration, Zeit. Phys. C 67, 183 (1995)
P. Abreu et al. , DELPHI Collaboration, Phys. Lett. B 357, 715 (1995)
D. Decamp et al. , ALEPH Collaboration, Phys. Lett. B 279, 411 (1992)
S. Wasserbaech, Nucl. Phys. B (Proc. Suppl.) 76, 107 (1999)
P. Abreu et al. , DELPHI Collaboration, Eur. Phys. J. C 14, 585 (2000)
G. Alexander et al. , OPAL Collaboration, Phys.Lett. B 374, 341 (1996); R. Balest et al. , CLEO Collaboration, Phys.Lett. B 388, 402 (1996); M. Acciarri et al. , L3 Collaboration, Phys.Lett. B 479, 67 (2000); R. Barate et al. , ALEPH Collaboration, Phys.Lett. B 414, 362 (1997)
P. Abreu et al. , DELPHI Collaboration, Eur. Phys. J. C 10, 201 (1999)
Author information
Consortia
Additional information
Received: 12 November 2003, Revised: 1 June 2004, Published online: 20 July 2004
Rights and permissions
About this article
Cite this article
The DELPHI Collaboration. A precise measurement of the tau lifetime. Eur. Phys. J. C 36, 283–296 (2004). https://doi.org/10.1140/epjc/s2004-01953-7
Issue Date:
DOI: https://doi.org/10.1140/epjc/s2004-01953-7