Measurement of the tau lepton lifetime

• Published in: Physics letters. B 1991-12, Vol.273 (3), p.355-366
• Main Authors: Acton, P.D., Anderson, K.J., Axen, D., Azuelos, G., Barker, G.J., Barlow, R.J., Batley, J.R., Behnke, T., Bella, G., Bethke, S., Bloodworth, I.J., Boden, B., Brun, R., Capiluppi, P., Charlton, D.G., Clarke, P.E.L., Conboy, J.E., Cooper, M., Cuffiani, M., Dallavalle, G.M., del Pozo, L.A., Deninno, M.M., Duchovni, E., Eckerlin, G., Fong, D.G., Fukunaga, C., Gascon, J., McGowan, R.F., Gorn, W., Grandi, C., Hagemann, J., Hawkes, C.M., Hemingway, R.J., Hobbs, J.D., Homer, R.J., Hou, S.R., Igo-Kemenes, P., Janissen, A.C., Jawahery, A., Jeffreys, P.W., Jimack, M., Jobes, M., Jones, R.W.L., Kawagoe, K., Kawamoto, T., Kellogg, R.G., Klem, D.E., Kokott, T.P., Köpke, L., Kowalewski, R., von Krogh, J., Lafferty, G.D., Le Du, P., Leblanc, P., Lennert, P., Letts, J., Loebinger, F.K., Lorazo, B., Losty, M.J., Lou, X.C., Maringer, G., Martin, A.J., Mättig, P., Maur, U., McNutt, J.R., Mes, H., Middleton, R.P., Mildenberger, J., Mir, R., Mohr, W., Nellen, B., Nozaki, M., Oakham, F.G., Ogren, H.O., Oh, H., Pinfold, J.L., Pitman, D., Poli, B., Prebys, E., Robins, S.A., Rossberg, S., Sasaki, M., Schenk, P., Schreiber, S., Settles, M., Shen, B.C., Sherwood, P., Shypit, R., Smith, T.J., Snow, G.A., Sobie, R., Springer, R.W., Strom, D., Turner, M.F., VanDalen, G.J., Wahl, C., Watson, N.K., Weber, M., Wingerter, I., Zorn, G.T.
• Format: Article
• Language: English
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/0370-2693(91)91695-R

The tau lepton lifetime has been measured using two independent techniques; an impact parameter analysis of the 1-prong decays and a decay length analysis of the 3-prong decays. Approximately 5 000 Z 0 decays to τ + τ − have been selected from the data collected with the OPAL detector at LEP during 1990. The results of the two statistically independent measurements are, respectively, τ 1=0.293 ± 0.013 (stat.)±0.013 (syst.) ps and τ 3=0.327±0.017 (stat.)±0.011 (syst.) ps. After combining the statistical and systematic errors for each analysis in quadrature, the weighted average lifetime is calculated to be τ τ =0.308 ± 0.013 ps.