Measurement of the [formula omitted] branching ratio and an upper limit on [formula omitted]

• Published in: Physics letters. B 1995, Vol.343 (1), p.444-452
• Main Authors: Lees, J.-P., Pietrzyk, B., Martinez, M., Pacheco, A., Natali, S., Raso, G., Selvaggi, G., Silvestris, L., Huang, X., Lin, J., Xu, R., Xue, S., Boudreau, J., Engelhardt, A., Frank, M., Ganis, G., Martin, E.B., Minten, A., Pusztaszeri, J.-F., Ranjard, F., Guicheney, C., Montret, J-C., Hansen, J.D., Hansen, J.R., Hansen, P.H., Møllerud, R., Simopoulou, E., Vayaki, A., Blondel, A., Bonneaud, G., Verderi, M., Candlin, D.J., Focardi, E., Delfino, M., Georgiopoulos, C., Bossi, F., Felici, G., Laurelli, P., Mannocchi, G., Murtas, F., Pepe-Altarelli, M., Colrain, P., Smith, K., Becker, U., Braun, O., Rensch, B., Stenzel, H., Dornan, P.J., Hassard, J.F., Moneta, L., Moutoussi, A., Brodbeck, T.J., Jackson, D., Nuttall, M., Sloan, T., Walther, S.M., Benchouk, C., Bonissent, A., Carr, J., Bauer, C., Dehning, B., Dietl, H., Jakobs, K., Lutz, G., Schröder, J., Schwarz, A.S., Cordier, A., Courault, F., Davier, M., Janot, P., Lefrançois, J., Park, H.J., Videau, I., Batignani, G., Bozzi, C., Ciulli, V., Foà, L., Forti, F., Vannini, C., Botterill, D.R., Locci, E., Renardy, J.-F., Schuller, J.-P., Si Mohand, D., Litke, A.M., Beddall, A., Koksal, A., Rankin, C., Cowan, G., Minguet-Rodriguez, J., Rivera, F., Smolik, L., Della Marina, R., Rothberg, J., Bellantoni, L., Grahl, J., Harton, J.L., Nachtman, J.M., Wu, X., Zheng, M.
• Format: Article
• Language: English
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/0370-2693(94)01584-Y

Using 1.45 million hadronic Z decays collected by the ALEPH experiment at LEP, the b → τ − ν - τ X branching ratio is measured to be 2.75 ± 0.30 ± 0.37%. In addition an upper limit of 1.8 × 10 −3 at 90% confidence level is placed upon the exclusive branching ratio of B − → τ − ν - τ . These measurements are consistent with SM expectations, and put the constraint tan β M h ± < 0.52 GeV −1 at 90% confidence level on all Type II two Higgs doublet models (such as the MSSM).