Cargando…

Measurement of the $e^+ e^- \to W^+ W^-$ cross section and W decay branching fractions at LEP

From a total data sample of 701.1 pb^-1 recorded with e+e- centre-of-mass energies of sqrt = 161-209 GeV with the OPAL detector at LEP, 11693 W-pair candidate events are selected. These data are used to obtain measurements of the W-pair production cross sections at 10 different centre-of-mass energi...

Descripción completa

Detalles Bibliográficos
Autores principales: Abbiendi, G., Ainsley, C., Akesson, P.F., Alexander, G., Anagnostou, G., Anderson, K.J., Asai, S., Axen, D., Bailey, I., Barberio, E., Barillari, T., Barlow, R.J., Batley, R.J., Bechtle, P., Behnke, T., Bell, Kenneth Watson, Bell, P.J., Bella, G., Bellerive, A., Benelli, G., Bethke, S., Biebel, O., Boeriu, O., Bock, P., Boutemeur, M., Braibant, S., Brown, Robert M., Burckhart, H.J., Campana, S., Capiluppi, P., Carnegie, R.K., Carter, A.A., Carter, J.R., Chang, C.Y., Charlton, D.G., Ciocca, C., Csilling, A., Cuffiani, M., Dado, S., Dallavalle, M., De Roeck, A., De Wolf, E.A., Desch, K., Dienes, B., Dubbert, J., Duchovni, E., Duckeck, G., Duerdoth, I.P., Etzion, E., Fabbri, F., Ferrari, P., Fiedler, F., Fleck, I., Ford, M., Frey, A., Gagnon, P., Gary, John William, Geich-Gimbel, C., Giacomelli, G., Giacomelli, P., Giunta, Marina, Goldberg, J., Gross, E., Grunhaus, J., Gruw, M., Gupta, A., Hajdu, C., Hamann, M., Hanson, G.G., Harel, A., Hauschild, M., Hawkes, C.M., Hawkings, R., Herten, G., Heuer, R.D., Hill, J.C., Horvath, D., Igo-Kemenes, P., Ishii, K., Jeremie, H., Jovanovic, P., Junk, T.R., Kanzaki, J., Karlen, D., Kawagoe, K., Kawamoto, T., Keeler, R.K., Kellogg, R.G., Kennedy, B.W., Kluth, S., Kobayashi, T., Kobel, M., Komamiya, S., Kramer, T., Krasznahorkay, A., Jr., Krieger, P., von Krogh, J., Kuhl, T., Kupper, M., Lafferty, G.D., Landsman, H., Lanske, D., Lellouch, D., Lettso, J., Levinson, L., Lillich, J., Lloyd, S.L., Loebinger, F.K., Lu, J., Ludwig, A., Ludwig, J., Mader, W., Marcellini, S., Martin, A.J., Mashimo, T., Mattig, Peter, McKenna, J., McPherson, R.A., Meijers, F., Menges, W., Merritt, F.S., Mes, H., Meyer, N., Michelini, A., Mihara, S., Mikenberg, G., Miller, D.J., Mohr, W., Mori, T., Mutter, A., Nagai, K., Nakamura, I., Nanjo, H., Neal, H.A., O'Neale, S.W., Oh, A., Oreglia, M.J., Orito, S., Pahl, C., Pasztor, G., Pater, J.R., Pilcher, J.E., Pinfold, J., Plane, D.E., Pooth, O., Przybycien, M., Quadt, A., Rabbertz, K., Rembser, C., Renkel, P., Roney, J.M., Rossi, A.M., Rozen, Y., Runge, K., Sachs, K., Saeki, T., Sarkisyan, E.K.G., Schaile, A.D., Schaile, O., Scharff-Hansen, P., Schieck, J., Schorner-Sadenius, T., Schroder, M., Schumacher, M., Seuster, R., Shears, T.G., Shen, B.C., Sherwood, P., Skuja, A., Smith, A.M., Sobie, R., Soldner-Rembold, S., Spano, F., Stahl, A., Strom, David M., Strohmer, R., Tarem, S., Tasevsky, M., Teuscher, R., Thomson, M.A., Torrence, E., Toya, D., Trigger, I., Trocsanyi, Z., Tsur, E., Turner-Watson, M.F., Ueda, I., Ujvari, B., Vollmer, C.F., Vannerem, P., Vertesi, R., Verzocchi, M., Voss, H., Vossebeld, J., Ward, C.P., Ward, D.R., Watkins, P.M., Watson, A.T., Watson, N.K., Wells, P.S., Wengler, T., Wermes, N., Wilson, G.W., Wilson, J.A., Wolf, G., Wyatt, T.R., Yamashita, S., Zer-Zion, D., Zivkovic, Lidija
Lenguaje:eng
Publicado: 2007
Materias:
Acceso en línea:https://dx.doi.org/10.1140/epjc/s10052-007-0442-0
http://cds.cern.ch/record/1050573
Descripción
Sumario:From a total data sample of 701.1 pb^-1 recorded with e+e- centre-of-mass energies of sqrt = 161-209 GeV with the OPAL detector at LEP, 11693 W-pair candidate events are selected. These data are used to obtain measurements of the W-pair production cross sections at 10 different centre-of-mass energies. The ratio of the measured cross sections to the Standard Model expectation is found to be: data/SM = 1.002 +- 0.011(stat.) +- 0.007(syst.) +- 0.005(theory), where the uncertainties are statistical, experimental systematics and theory systematics respectively. The data are used to determine the W boson branching fractions, which are found to be consistent with lepton universality of the charged current interaction. Assuming lepton universality, the branching ratio to hadrons is determined to be 67.41 +- 0.37(stat.) +- 0.23(syst.)%, from which the CKM matrix element Vcs is determined to be 0.96+-0.017(stat.)+-0.012(syst.). The differential cross section as a function of the W^- production angle is measured for the qqev and qqmv final states. The results described in this paper are consistent with the expectations from the Standard Model.