A measurement of the tau lifetime

• Published in: Physics letters. B 1993-03, Vol.302 (2), p.356-368
• Main Authors: Alvsvaag, S.J., Amaldi, U., Barate, R., Baroncelli, A., Barrio, J.A., Bloch, D., Booth, P.S.L., Bostjancic, B., Bowcock, T.J.V., Bugge, L., Buran, T., Camacho Rozas, A.J., Campion, R., Cao, F., Carroll, L., Chan, A., Chauveau, J., Chelkov, G.A., Contri, R., Crawley, H.B., Dalmagne, B., Daubie, E., Daum, A., Delpierre, P., De Clercq, C., Donszelmann, M., Ekelof, T., Engel, J.-P., Fenyuk, A., Fontanelli, F., Forbes, K.A.J., Fousset, J.-L., Gamba, D., Gaspar, C., Gavillet, Ph, Golob, B., Grosdidier, G., Hamacher, K., Herr, H., Hietanen, I., Higon, E., Hilke, H.J., Holmes, R., Ioannou, P., Iversen, P.-S., Jarry, P., Karvelas, E., Kesteman, J., Khovanski, N.N., Kluit, P., Kurvinen, K., Lanceri, L., Lauhakangas, R., Leitner, R., Lemoigne, Y., Lemonne, J., Loerstad, B., Maltezos, A., Marco, J., Matorras, F., Mc Nay, R., Meyer, W.T., Monge, M.R., Mueller, H., Nikolaenko, V., Olshevski, A.G., Ostankov, A., Pingot, O., Pol, M.E., Polok, G., Privitera, P., Richardson, M., Rosenberg, E.I., Rossi, U., Rosso, E., Roudeau, P., Sannino, M., Sette, G., Stichelbaut, F., Stocchi, A., Tchikilev, O., Timofeev, V.G., Toet, D.Z., Trischuk, W., Turluer, M.-L., Ueberschaer, S., Valls Ferrer, J.A., Ventura, L., Verbeure, F., Vilanova, D., Vodopyanov, A.S., Voutilainen, M., Wahlen, H., Weilhammer, P., Wetherell, A.M., Williams, W.S.C., Yepes, P., Zito, M., Zukanovich Funchal, R., Zumerle, G.
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; High Energy Physics - Experiment; Leptons; Physics; Properties of specific particles; The physics of elementary particles and fields
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/0370-2693(93)90409-B

The tau lepton lifetime is measured using four different methods with the DELPHI detector. Three measurements using one prong decays are combined, accounting for correlations, resulting in τ τ =298 ±7 (stat.)±4 (syst.) fs while the decay length distribution of three prong decays gives π π =298±13 (stat)±(syst.) fs. The combined result is τ τ =298±7 fs. The ratio of the Fermi coupling constant from tau decay relative to that from muon decay is found to be 0.985±0.013, compatible with lepton universality.