Advertisement

A precise measurement of the tau lifetime

  • The DELPHI Collaboration
experimental physics

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 \(\tau_\tau = 290.9\pm 1.4_{\mathrm{stat}} \pm 1.0_{\mathrm{sys}} \mathrm{fs}\).

Keywords

Charged Particle Precise Measurement Decay Channel LEP1 Data Taus Decay 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Y.S. Tsai, Phys. Rev. D 4, 2821 (1971); H.B. Thacker and J.J. Sakurai, Phys. Lett. B 36, 103 (1971)CrossRefGoogle Scholar
  2. 2.
    P. Abreu et al. , DELPHI Collaboration, Phys. Lett. B 365, 448 (1996)CrossRefGoogle Scholar
  3. 3.
    N. Bingefors et al. , Nucl. Instr. and Meth. A 328, 447 (1993); V. Chabaud et al. , Nucl. Instr. and Meth. A 368, 314 (1996)Google Scholar
  4. 4.
    P. Abreu et al. , DELPHI Collaboration, Phys. Lett. B 302, 356 (1993)CrossRefGoogle Scholar
  5. 5.
    K. Hagiwara Phys. Rev. D 66, 010001 (2002)Google Scholar
  6. 6.
    S. Jadach, B.F.L. Ward and Z. Was, Comput. Phys. Commun. 79, 503 (1994)CrossRefGoogle Scholar
  7. 7.
    S. Jadach et al. , Comput. Phys. Commun. 76, 361 (1993)CrossRefGoogle Scholar
  8. 8.
    J.E. Campagne and R. Zitoun, Zeit. Phys. C 43, 469 (1989)Google Scholar
  9. 9.
    F.A. Berends, R. Kleiss and W. Hollik, Nucl. Phys. B 304, 712 (1988)CrossRefGoogle Scholar
  10. 10.
    S. Jadach, W. Placzek and B.F.L. Ward, Phys. Lett. B 390, 298 (1997)CrossRefGoogle Scholar
  11. 11.
    P. Abreu et al. , DELPHI Collaboration, Zeit. Phys. C 73, 11 (1996)CrossRefGoogle Scholar
  12. 12.
    F.A. Berends, P.H. Daverveldt and R. Kleiss, Phys. Lett. B 148, 489 (1984); Comput. Phys. Commun. 40, 271 (1986)CrossRefGoogle Scholar
  13. 13.
    T. Alderweireld et al. , CERN Report CERN-2000-009, 219 (2000)Google Scholar
  14. 14.
    P. Abreu et al. , DELPHI Collaboration, Nucl. Instr. and Meth. A 378, 57 (1996)Google Scholar
  15. 15.
    P. Aarnio et al. , DELPHI Collaboration, Nucl. Instr. and Meth. A 303, 233 (1991)Google Scholar
  16. 16.
    P. Abreu et al. , DELPHI Collaboration, Eur. Phys. J. C 10, 415 (1999)CrossRefGoogle Scholar
  17. 17.
    P. Abreu et al. , DELPHI Collaboration, Zeit. Phys. C 67, 183 (1995)Google Scholar
  18. 18.
    P. Abreu et al. , DELPHI Collaboration, Phys. Lett. B 357, 715 (1995)CrossRefGoogle Scholar
  19. 19.
    D. Decamp et al. , ALEPH Collaboration, Phys. Lett. B 279, 411 (1992)CrossRefGoogle Scholar
  20. 20.
    S. Wasserbaech, Nucl. Phys. B (Proc. Suppl.) 76, 107 (1999)CrossRefGoogle Scholar
  21. 21.
    P. Abreu et al. , DELPHI Collaboration, Eur. Phys. J. C 14, 585 (2000)Google Scholar
  22. 22.
    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)CrossRefGoogle Scholar
  23. 23.
    P. Abreu et al. , DELPHI Collaboration, Eur. Phys. J. C 10, 201 (1999)CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin/Heidelberg 2004

Authors and Affiliations

  • The DELPHI Collaboration

There are no affiliations available

Personalised recommendations