Summary
The precisions of τ lifetime measurements have increased remarkably in the last several years. The techniques which lead to these results are summarized and compared, together with results obtained by different experiments from use of these methods. By combining the recent, and previous lifetime values an updated world average lifetime of ττ=(927.7±1.6) fs is obtained, which is in good agreement with the prediction derived from the τ electronic branching ratio through the assumption of τ-μ lepton universality.
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References
MARK II Collaboration (J. A. Jaros et al.),Phys. Rev. Lett.,51 (1983) 955.
Particle Data Group (M. Aguilar-Benitez et al.),Phys. Rev. D,45 (1992) 1.
Marciano W. J.,Phys. Rev. D,45 (1992) 721.
See the reviews byFerrante I. (IPS methods),White C. G. (CLEO results),Andreazza A. (IPD method),Biasini M. (IP method) andCharlesworth C. E. K. (DL method),Proceedings of the III Workshop on Tau Lepton Physics, September 19–22, 1994, Nucl. Phys. B (Proc. Suppl.),40 (1995) 299.
SLD Collaboration (K. Abe et al.),Measurement of the Tau Lifetime at SLD, SLAC-PUB-95-6767 (25 April 1995), submitted toPhys. Rev.
ALEPH Collaboration (D. Buskilic et al.),Phys. Lett. B,297 (1992) 432.
CLEO Collaboration (M. Battle et al.),Phys. Lett. B,291 (1992) 488.
DELPHI Collaboration (P. Abreu et al.),Phys. Lett. B,302 (1993) 356.
L3 Collaboration (O. Adriani et al.),Phys. Rep.,236 (1993) 1.
OPAL Collaboration (R. Akers et al.),Phys. Lett. B,338 (1994) 497.
The combination of results with previous measurements, including adjustments to older DL measurements, for the updated τ mass, was performed by S. Wasserbaech and is contained inDavier M.,Proceedings of the III Workshop on Tau Lepton Physics, September 19–22, 1994,Nucl. Phys. B (Proc. Suppl.),40 (1995) 395.
SeeGeweniger C.,Tau Branching Ratios, paper presented at theVI International Symposium on Heavy-Flavour Physics, Pisa, June 6–10, 1995; the value of the τ electronic branching ratio in this presentation was (17.79±0.08)%.
Qi N.,Proceedings of the III Workshop on Tau Lepton Physics, September 19–22, 1994,Nucl. Phys. B (Proc. Suppl.),40 (1995) 387.
Britton D. I. et al., Phys. Lett. B,68 (1992) 3000;Czapek G. et al., Phys. Rev. Lett.,70 (1993) 17.
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Weber, P. Measurements of the τ lepton lifetime. Nuov Cim A 109, 925–938 (1996). https://doi.org/10.1007/BF02823634
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DOI: https://doi.org/10.1007/BF02823634