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203. The clonal and mutational evolution spectrum of primary triple-negative breast cancers

Author

Shah, S., Roth, A., Goya, R., Oloumi, A., Ha, G., Zhao, Y., Turashvili, G., Ding, J., Tse, K., Haffari, G., Bashashati, A., Prentice, L., Khattra, J., Burleigh, A., Yap, D., Bernard, V., McPherson, A., Shumansky, K., Crisan, A., Giuliany, R., Heravi-Moussavi, A., Rosner, J., Lai, D., Birol, I., Varhol, Richard, Tam, A., Dhalla, N., Zeng, T., Ma, K., Chan, S., Griffith, M., Moradian, A., Cheng, S., Morin, G., Watson, P., Gelmon, K., Chia, S., Chin, S., Curtis, C., Rueda, O., Pharoah, P., Damaraju, S., MacKey, J., Hoon, K., Harkins, T., Tadigotla, V., Sigaroudinia, M., Gascard, P., Tlsty, T., Costello, J., Meyer, I., Eaves, C., Wasserman, W., Jones, S., Huntsman, D., Hirst, M., Caldas, C., Marra, M., Aparicio, S., Shah, S., Roth, A., Goya, R., Oloumi, A., Ha, G., Zhao, Y., Turashvili, G., Ding, J., Tse, K., Haffari, G., Bashashati, A., Prentice, L., Khattra, J., Burleigh, A., Yap, D., Bernard, V., McPherson, A., Shumansky, K., Crisan, A., Giuliany, R., Heravi-Moussavi, A., Rosner, J., Lai, D., Birol, I., Varhol, Richard, Tam, A., Dhalla, N., Zeng, T., Ma, K., Chan, S., Griffith, M., Moradian, A., Cheng, S., Morin, G., Watson, P., Gelmon, K., Chia, S., Chin, S., Curtis, C., Rueda, O., Pharoah, P., Damaraju, S., MacKey, J., Hoon, K., Harkins, T., Tadigotla, V., Sigaroudinia, M., Gascard, P., Tlsty, T., Costello, J., Meyer, I., Eaves, C., Wasserman, W., Jones, S., Huntsman, D., Hirst, M., Caldas, C., Marra, M., and Aparicio, S.

Abstract

Primary triple-negative breast cancers (TNBCs), a tumour type defined by lack of oestrogen receptor, progesterone receptor and ERBB2 gene amplification, represent approximately 16% of all breast cancers. Here we show in 104 TNBC cases that at the time of diagnosis these cancers exhibit a wide and continuous spectrum of genomic evolution, with some having only a handful of coding somatic aberrations in a few pathways, whereas others contain hundreds of coding somatic mutations. High-throughput RNA sequencing (RNA-seq) revealed that only approximately 36% of mutations are expressed. Using deep re-sequencing measurements of allelic abundance for 2,414 somatic mutations, we determine for the first time-to our knowledge-in an epithelial tumour subtype, the relative abundance of clonal frequencies among cases representative of the population. We show that TNBCs vary widely in their clonal frequencies at the time of diagnosis, with the basal subtype of TNBC showing more variation than non-basal TNBC. Although p53 (also known as TP53), PIK3CA and PTEN somatic mutations seem to be clonally dominant compared to other genes, in some tumours their clonal frequencies are incompatible with founder status. Mutations in cytoskeletal, cell shape and motility proteins occurred at lower clonal frequencies, suggesting that they occurred later during tumour progression. Taken together, our results show that understanding the biology and therapeutic responses of patients with TNBC will require the determination of individual tumour clonal genotypes. © 2012 Macmillan Publishers Limited. All rights reserved.

Published
2012

204. Measurements of $R_{b}$, $A_{FB}^{b}$ and $A_{FB}^{c}$ in $e^{+}e^{-}$ Collisions at 130-189 GeV

Author

Abbiendi, G., Ackerstaff, K., Akesson, P.F., Alexander, G., Allison, John, Anderson, K.J., Arcelli, S., Asai, S., Ashby, S.F., Axen, D., Azuelos, G., Bailey, I., Ball, A.H., Barberio, E., Barlow, Roger J., Batley, J.R., Baumann, S., Behnke, T., Bell, Kenneth Watson, Bella, G., Bellerive, A., Bentvelsen, S., Bethke, S., Betts, S., Biebel, O., Biguzzi, A., Bloodworth, I.J., Bock, P., Bohme, J., Boeriu, O., Bonacorsi, D., Boutemeur, M., Braibant, S., Bright-Thomas, P., Brigliadori, L., Brown, Robert M., Burckhart, H.J., Capiluppi, P., Carnegie, R.K., Carter, A.A., Carter, J.R., Chang, C.Y., Charlton, David G., Chrisman, D., Ciocca, C., Clarke, P.E.L., Clay, E., Cohen, I., Conboy, J.E., Cooke, O.C., Couchman, J., Couyoumtzelis, C., Coxe, R.L., Cuffiani, M., Dado, S., Dallavalle, G.Marco, Dallison, S., Davis, R., de Roeck, A., Dervan, P., Desch, K., Dienes, B., Dixit, M.S., Donkers, M., Dubbert, J., Duchovni, E., Duckeck, G., Duerdoth, I.P., Estabrooks, P.G., Etzion, E., Fabbri, F., Fanfani, A., Fanti, M., Faust, A.A., Feld, L., Ferrari, P., Fiedler, F., Fierro, M., Fleck, I., Frey, A., Furtjes, A., Futyan, D.I., Gagnon, P., Gary, J.W., Gaycken, G., Geich-Gimbel, C., Giacomelli, G., Giacomelli, P., Gingrich, D.M., Glenzinski, D., Goldberg, J., Gorn, W., Grandi, C., Graham, K., Gross, E., Grunhaus, J., Gruwe, M., Hajdu, C., Hanson, G.G., Hansroul, M., Hapke, M., Harder, K., Harel, A., Hargrove, C.K., Harin-Dirac, M., Hauschild, M., Hawkes, C.M., Hawkings, R., Hemingway, R.J., Herten, G., Heuer, R.D., Hildreth, M.D., Hill, J.C., Hobson, P.R., Hocker, James Andrew, Hoffman, Kara Dion, Homer, R.J., Honma, A.K., Horvath, D., Hossain, K.R., Howard, R., Huntemeyer, P., Igo-Kemenes, P., Imrie, D.C., Ishii, K., Jacob, F.R., Jawahery, A., Jeremie, H., Jimack, M., Jones, C.R., Jovanovic, P., Junk, T.R., Kanaya, N., Kanzaki, J., Karapetian, G., Karlen, D., Kartvelishvili, V., Kawagoe, K., Kawamoto, T., Kayal, P.I., Keeler, R.K., Kellogg, R.G., Kennedy, B.W., Kim, D.H., Klier, A., Kobayashi, T., Kobel, M., Kokott, T.P., Kolrep, M., Komamiya, S., Kowalewski, Robert V., Kress, T., Krieger, P., von Krogh, J., Kuhl, T., Kupper, M., Kyberd, P., Lafferty, G.D., Landsman, H., Lanske, D., Lauber, J., Lawson, I., Layter, J.G., Lellouch, D., Letts, J., Levinson, L., Liebisch, R., Lillich, J., List, B., Littlewood, C., Lloyd, A.W., Lloyd, S.L., Loebinger, F.K., Long, G.D., Losty, M.J., Lu, J., Ludwig, J., Macchiolo, A., Macpherson, A., Mader, W., Mannelli, M., Marcellini, S., Marchant, T.E., Martin, A.J., Martin, J.P., Martinez, G., Mashimo, T., Mattig, Peter, McDonald, W.John, McKenna, J., Mckigney, E.A., McMahon, T.J., McPherson, R.A., Meijers, F., Mendez-Lorenzo, P., Merritt, F.S., Mes, H., Meyer, I., Michelini, A., Mihara, S., Mikenberg, G., Miller, D.J., Mohr, W., Montanari, A., Mori, T., Nagai, K., Nakamura, I., Neal, H.A., Nisius, R., O'Neale, S.W., Oakham, F.G., Odorici, F., Ogren, H.O., Okpara, A., Oreglia, M.J., Orito, S., Pasztor, G., Pater, J.R., Patrick, G.N., Patt, J., Perez-Ochoa, R., Petzold, S., Pfeifenschneider, P., Pilcher, J.E., Pinfold, J., Plane, David E., Poli, B., Polok, J., Przybycien, M., Quadt, A., Rembser, C., Rick, H., Robins, S.A., Rodning, N., Roney, J.M., Rosati, S., Roscoe, K., Rossi, A.M., Rozen, Y., Runge, K., Runolfsson, O., Rust, D.R., Sachs, K., Saeki, T., Sahr, O., Sang, W.M., Sarkisian, E.K.G., Sbarra, C., Schaile, A.D., Schaile, O., Scharff-Hansen, P., Schieck, J., Schmitt, S., Schoning, A., Schroder, Matthias, Schumacher, M., Schwick, C., Scott, W.G., Seuster, R., Shears, T.G., Shen, B.C., Shepherd-Themistocleous, C.H., Sherwood, P., Siroli, G.P., Skuja, A., Smith, A.M., Snow, G.A., Sobie, R., Soldner-Rembold, S., Spagnolo, S., Sproston, M., Stahl, A., Stephens, K., Stoll, K., Strom, David M., Strohmer, R., Surrow, B., Talbot, S.D., Taras, P., Tarem, S., Teuscher, R., Thiergen, M., Thomas, J., Thomson, M.A., Torrence, E., Towers, S., Trefzger, T., Trigger, I., Trocsanyi, Z., Tsur, E., Turner-Watson, M.F., Ueda, I., Van Kooten, Rick J., Vannerem, P., Verzocchi, M., Voss, H., Wackerle, F., Waller, D., Ward, C.P., Ward, D.R., Watkins, P.M., Watson, A.T., Watson, N.K., Wells, P.S., Wengler, T., Wermes, N., Wetterling, D., White, J.S., Wilson, G.W., Wilson, J.A., Wyatt, T.R., Yamashita, S., Zacek, V., and Zer-Zion, D.

Subjects
High Energy Physics::Phenomenology, High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment
Abstract

The cross-section ratio Rb=sigma(e+e- to b-antib)/sigma(e+e- to q-antiq) andthe bottom and charm forward-backward asymmetries AFB^b and AFB^c are measuredusing event samples collected by the OPAL detector at centre-of-mass energiesbetween 130 and 189 GeV. Events with bottom quark production are selected witha secondary vertex tag, and a hemisphere charge algorithm is used to extractAFB^b. In addition, the bottom and charm asymmetries are measured using leptonsfrom semileptonic decays of heavy hadrons and pions from D*+ to D0pi+ decays.The results are in agreement with the Standard Model predictions. The cross-section ratio Rb=sigma(e+e- to b-antib)/sigma(e+e- to q-antiq) and the bottom and charm forward-backward asymmetries AFB^b and AFB^c are measured using event samples collected by the OPAL detector at centre-of-mass energies between 130 and 189 GeV. Events with bottom quark production are selected with a secondary vertex tag, and a hemisphere charge algorithm is used to extract AFB^b. In addition, the bottom and charm asymmetries are measured using leptons from semileptonic decays of heavy hadrons and pions from D*+ to D0pi+ decays. The results are in agreement with the Standard Model predictions.

Published
2000

205. Z boson pair production in $e^{+}e^{-}$ collisions at $\sqrt{s}$ = 183 and 189 GeV

Author

Abbiendi, G., Ackerstaff, K., Akesson, P.F., Alexander, G., Allison, John, Anderson, K.J., Arcelli, S., Asai, S., Ashby, S.F., Axen, D., Azuelos, G., Bailey, I., Ball, A.H., Barberio, E., Barlow, Roger J., Batley, J.R., Baumann, S., Behnke, T., Bell, Kenneth Watson, Bella, G., Bellerive, A., Bentvelsen, S., Bethke, S., Biebel, O., Biguzzi, A., Bloodworth, I.J., Bock, P., Bohme, J., Boeriu, O., Bonacorsi, D., Boutemeur, M., Braibant, S., Bright-Thomas, P., Brigliadori, L., Brown, Robert M., Burckhart, H.J., Cammin, J., Capiluppi, P., Carnegie, R.K., Carter, A.A., Carter, J.R., Chang, C.Y., Charlton, David G., Chrisman, D., Ciocca, C., Clarke, P.E.L., Clay, E., Cohen, I., Cooke, O.C., Couchman, J., Couyoumtzelis, C., Coxe, R.L., Cuffiani, M., Dado, S., Dallavalle, G.Marco, Dallison, S., Davis, R., de Roeck, A., Dervan, P., Desch, K., Dienes, B., Dixit, M.S., Donkers, M., Dubbert, J., Duchovni, E., Duckeck, G., Duerdoth, I.P., Estabrooks, P.G., Etzion, E., Fabbri, F., Fanfani, A., Fanti, M., Faust, A.A., Feld, L., Ferrari, P., Fiedler, F., Fierro, M., Fleck, I., Frey, A., Furtjes, A., Futyan, D.I., Gagnon, P., Gary, J.W., Gaycken, G., Geich-Gimbel, C., Giacomelli, G., Giacomelli, P., Gingrich, D.M., Glenzinski, D., Goldberg, J., Gorn, W., Grandi, C., Graham, K., Gross, E., Grunhaus, J., Gruwe, M., Gunther, P.O., Hajdu, C., Hanson, G.G., Hansroul, M., Hapke, M., Harder, K., Harel, A., Hargrove, C.K., Harin-Dirac, M., Hauke, A., Hauschild, M., Hawkes, C.M., Hawkings, R., Hemingway, R.J., Hensel, C., Herten, G., Heuer, R.D., Hildreth, M.D., Hill, J.C., Hobson, P.R., Hocker, James Andrew, Hoffman, Kara Dion, Homer, R.J., Honma, A.K., Horvath, D., Hossain, K.R., Howard, R., Huntemeyer, P., Igo-Kemenes, P., Imrie, D.C., Ishii, K., Jacob, F.R., Jawahery, A., Jeremie, H., Jimack, M., Jones, C.R., Jovanovic, P., Junk, T.R., Kanaya, N., Kanzaki, J., Karapetian, G., Karlen, D., Kartvelishvili, V., Kawagoe, K., Kawamoto, T., Kayal, P.I., Keeler, R.K., Kellogg, R.G., Kennedy, B.W., Kim, D.H., Klein, K., Klier, A., Kobayashi, T., Kobel, M., Kokott, T.P., Kolrep, M., Komamiya, S., Kowalewski, Robert V., Kress, T., Krieger, P., von Krogh, J., Kuhl, T., Kupper, M., Kyberd, P., Lafferty, G.D., Landsman, H., Lanske, D., Lawson, I., Layter, J.G., Leins, A., Lellouch, D., Letts, J., Levinson, L., Liebisch, R., Lillich, J., List, B., Littlewood, C., Lloyd, A.W., Lloyd, S.L., Loebinger, F.K., Long, G.D., Losty, M.J., Lu, J., Ludwig, J., Macchiolo, A., Macpherson, A., Mader, W., Mannelli, M., Marcellini, S., Marchant, T.E., Martin, A.J., Martin, J.P., Martinez, G., Mashimo, T., Mattig, Peter, McDonald, W.John, McKenna, J., McMahon, T.J., McPherson, R.A., Meijers, F., Mendez-Lorenzo, P., Merritt, F.S., Mes, H., Meyer, I., Michelini, A., Mihara, S., Mikenberg, G., Miller, D.J., Mohr, W., Montanari, A., Mori, T., Nagai, K., Nakamura, I., Neal, H.A., Nisius, R., O'Neale, S.W., Oakham, F.G., Odorici, F., Ogren, H.O., Okpara, A., Oreglia, M.J., Orito, S., Pasztor, G., Pater, J.R., Patrick, G.N., Patt, J., Perez-Ochoa, R., Pfeifenschneider, P., Pilcher, J.E., Pinfold, J., Plane, David E., Poli, B., Polok, J., Przybycien, M., Quadt, A., Rembser, C., Rick, H., Robins, S.A., Rodning, N., Roney, J.M., Rosati, S., Roscoe, K., Rossi, A.M., Rozen, Y., Runge, K., Runolfsson, O., Rust, D.R., Sachs, K., Saeki, T., Sahr, O., Sang, W.M., Sarkisian, E.K.G., Sbarra, C., Schaile, A.D., Schaile, O., Scharff-Hansen, P., Schmitt, S., Schoning, A., Schroder, Matthias, Schumacher, M., Schwick, C., Scott, W.G., Seuster, R., Shears, T.G., Shen, B.C., Shepherd-Themistocleous, C.H., Sherwood, P., Siroli, G.P., Skuja, A., Smith, A.M., Snow, G.A., Sobie, R., Soldner-Rembold, S., Spagnolo, S., Sproston, M., Stahl, A., Stephens, K., Stoll, K., Strom, David M., Strohmer, R., Surrow, B., Talbot, S.D., Tarem, S., Taylor, R.J., Teuscher, R., Thiergen, M., Thomas, J., Thomson, M.A., Torrence, E., Towers, S., Trefzger, T., Trigger, I., Trocsanyi, Z., Tsur, E., Turner-Watson, M.F., Ueda, I., Van Kooten, Rick J., Vannerem, P., Verzocchi, M., Voss, H., Waller, D., Ward, C.P., Ward, D.R., Watkins, P.M., Watson, A.T., Watson, N.K., Wells, P.S., Wengler, T., Wermes, N., Wetterling, D., White, J.S., Wilson, G.W., Wilson, J.A., Wyatt, T.R., Yamashita, S., Zacek, V., and Zer-Zion, D.

Subjects
High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment
Abstract

A study of Z boson pair production in e+e- annihilation at center-of-mass energies near 183 GeV and 189 GeV is reported. Final states containing only leptons, (l+l-l+l- and l+l-nu nubar), quark and lepton pairs, (q qbar l+l-, q qbar nu nubar) and the all-hadronic final state (q qbar q qbar) are considered. In all states with at least one Z boson decaying hadronically, q qbar and b bbar final states are considered separately using lifetime and event-shape tags, thereby improving the cross-section measurement. At sqrt(s) = 189 GeV the Z-pair cross section was measured to be 0.80 (+0.14-0.13, stat.) (+0.06-0.05, syst.) pb, consistent with the Standard Model prediction. At sqrt(s) = 183 GeV the 95.L. upper limit is 0.55 pb. Limits on anomalous ZZgamma and ZZZ couplings are derived. A study of Z boson pair production in e + e − annihilation at center-of-mass energies near 183 GeV and 189 GeV is reported. Final states containing only leptons, (ℓ + ℓ − ℓ + ℓ − and ℓ + ℓ − ν ν ), quark and lepton pairs, ( q q ℓ + ℓ − , q q ν ν ) and the all-hadronic final state ( q q q q ) are considered. In all states with at least one Z boson decaying hadronically, q q and b b final states are considered separately using lifetime and event-shape tags, thereby improving the cross-section measurement. At s =189 GeV the Z-pair cross section was measured to be 0.80 +0.14 −0.13 ( stat. ) +0.06 −0.05 ( syst. ) pb , consistent with the Standard Model prediction. At s =183 GeV the 95% C.L. upper limit is 0.55 pb . Limits on anomalous ZZ γ and ZZZ couplings are derived. A study of Z boson pair production in e+e- annihilation at center-of-mass energies near 183 GeV and 189 GeV is reported. Final states containing only leptons, (l+l-l+l- and l+l-nu nubar), quark and lepton pairs, (q qbar l+l-, q qbar nu nubar) and the all-hadronic final state (q qbar q qbar) are considered. In all states with at least one Z boson decaying hadronically, q qbar and b bbar final states are considered separately using lifetime and event-shape tags, thereby improving the cross-section measurement. At sqrt(s) = 189 GeV the Z-pair cross section was measured to be 0.80 (+0.14-0.13, stat.) (+0.06-0.05, syst.) pb, consistent with the Standard Model prediction. At sqrt(s) = 183 GeV the 95% C.L. upper limit is 0.55 pb. Limits on anomalous ZZgamma and ZZZ couplings are derived.

Published
2000

206. Measurement of |$V_{cb}$| using $\overline{B}^{0} \to D^{*+}l^{-}\overline{\nu}$ decays

Author

Abbiendi, G., Ackerstaff, K., Akesson, P.F., Alexander, G., Allison, John, Anderson, K.J., Arcelli, S., Asai, S., Ashby, S.F., Axen, D., Azuelos, G., Bailey, I., Ball, A.H., Barberio, E., Barlow, Roger J., Batley, J.R., Baumann, S., Behnke, T., Bell, Kenneth Watson, Bella, G., Bellerive, A., Bentvelsen, S., Bethke, S., Biebel, O., Biguzzi, A., Bloodworth, I.J., Bock, P., Bohme, J., Boeriu, O., Bonacorsi, D., Boutemeur, M., Braibant, S., Bright-Thomas, P., Brigliadori, L., Brown, Robert M., Burckhart, H.J., Cammin, J., Capiluppi, P., Carnegie, R.K., Carter, A.A., Carter, J.R., Chang, C.Y., Charlton, David G., Chrisman, D., Ciocca, C., Clarke, P.E.L., Clay, E., Cohen, I., Cooke, O.C., Couchman, J., Couyoumtzelis, C., Coxe, R.L., Cuffiani, M., Dado, S., Dallavalle, G.Marco, Dallison, S., Davis, R., de Roeck, A., Dervan, P., Desch, K., Dienes, B., Dixit, M.S., Donkers, M., Dubbert, J., Duchovni, E., Duckeck, G., Duerdoth, I.P., Estabrooks, P.G., Etzion, E., Fabbri, F., Fanfani, A., Fanti, M., Faust, A.A., Feld, L., Ferrari, P., Fiedler, F., Fierro, M., Fleck, I., Frey, A., Furtjes, A., Futyan, D.I., Gagnon, P., Gary, J.W., Gaycken, G., Geich-Gimbel, C., Giacomelli, G., Giacomelli, P., Gingrich, D.M., Glenzinski, D., Goldberg, J., Gorn, W., Grandi, C., Graham, K., Gross, E., Grunhaus, J., Gruwe, M., Gunther, P.O., Hajdu, C., Hanson, G.G., Hansroul, M., Hapke, M., Harder, K., Harel, A., Hargrove, C.K., Harin-Dirac, M., Hauke, A., Hauschild, M., Hawkes, C.M., Hawkings, R., Hemingway, R.J., Hensel, C., Herten, G., Heuer, R.D., Hildreth, M.D., Hill, J.C., Hobson, P.R., Hocker, James Andrew, Hoffman, Kara Dion, Homer, R.J., Honma, A.K., Horvath, D., Hossain, K.R., Howard, R., Huntemeyer, P., Igo-Kemenes, P., Imrie, D.C., Ishii, K., Jacob, F.R., Jawahery, A., Jeremie, H., Jimack, M., Jones, C.R., Jovanovic, P., Junk, T.R., Kanaya, N., Kanzaki, J., Karapetian, G., Karlen, D., Kartvelishvili, V., Kawagoe, K., Kawamoto, T., Kayal, P.I., Keeler, R.K., Kellogg, R.G., Kennedy, B.W., Kim, D.H., Klein, K., Klier, A., Kobayashi, T., Kobel, M., Kokott, T.P., Kolrep, M., Komamiya, S., Kowalewski, Robert V., Kress, T., Krieger, P., von Krogh, J., Kuhl, T., Kupper, M., Kyberd, P., Lafferty, G.D., Landsman, H., Lanske, D., Lawson, I., Layter, J.G., Leins, A., Lellouch, D., Letts, J., Levinson, L., Liebisch, R., Lillich, J., List, B., Littlewood, C., Lloyd, A.W., Lloyd, S.L., Loebinger, F.K., Long, G.D., Losty, M.J., Lu, J., Ludwig, J., Macchiolo, A., Macpherson, A., Mader, W., Mannelli, M., Marcellini, S., Marchant, T.E., Martin, A.J., Martin, J.P., Martinez, G., Mashimo, T., Mattig, Peter, McDonald, W.John, McKenna, J., McMahon, T.J., McPherson, R.A., Meijers, F., Mendez-Lorenzo, P., Merritt, F.S., Mes, H., Meyer, I., Michelini, A., Mihara, S., Mikenberg, G., Miller, D.J., Mohr, W., Montanari, A., Mori, T., Nagai, K., Nakamura, I., Neal, H.A., Nisius, R., O'Neale, S.W., Oakham, F.G., Odorici, F., Ogren, H.O., Okpara, A., Oreglia, M.J., Orito, S., Pasztor, G., Pater, J.R., Patrick, G.N., Patt, J., Perez-Ochoa, R., Pfeifenschneider, P., Pilcher, J.E., Pinfold, J., Plane, David E., Poli, B., Polok, J., Przybycien, M., Quadt, A., Rembser, C., Rick, H., Robins, S.A., Rodning, N., Roney, J.M., Rosati, S., Roscoe, K., Rossi, A.M., Rozen, Y., Runge, K., Runolfsson, O., Rust, D.R., Sachs, K., Saeki, T., Sahr, O., Sang, W.M., Sarkisian, E.K.G., Sbarra, C., Schaile, A.D., Schaile, O., Scharff-Hansen, P., Schmitt, S., Schoning, A., Schroder, Matthias, Schumacher, M., Schwick, C., Scott, W.G., Seuster, R., Shears, T.G., Shen, B.C., Shepherd-Themistocleous, C.H., Sherwood, P., Siroli, G.P., Skuja, A., Smith, A.M., Snow, G.A., Sobie, R., Soldner-Rembold, S., Spagnolo, S., Sproston, M., Stahl, A., Stephens, K., Stoll, K., Strom, David M., Strohmer, R., Surrow, B., Talbot, S.D., Tarem, S., Taylor, R.J., Teuscher, R., Thiergen, M., Thomas, J., Thomson, M.A., Torrence, E., Towers, S., Trefzger, T., Trigger, I., Trocsanyi, Z., Tsur, E., Turner-Watson, M.F., Ueda, I., Van Kooten, Rick J., Vannerem, P., Verzocchi, M., Voss, H., Waller, D., Ward, C.P., Ward, D.R., Watkins, P.M., Watson, A.T., Watson, N.K., Wells, P.S., Wengler, T., Wermes, N., Wetterling, D., White, J.S., Wilson, G.W., Wilson, J.A., Wyatt, T.R., Yamashita, S., Zacek, V., and Zer-Zion, D.

Subjects
Particle Physics - Experiment
Abstract

The magnitude of the Cabibbo-Kobayashi-Maskawa matrix element Vcb has been measured using B0 to D*l nu decays recorded on the Z0 peak using the OPAL detector at LEP. The D* to D0 pi+ decays were reconstructed both in the particular decay modes D0 to K- pi+ and D0 to K- pi+ pi- and via an inclusive technique. The product of |Vcb| and the decay form factor of the B0 to D* l nu transition at zero recoil F(1) was measured to be F(1)|Vcb| = (37.1+-1.0+-2.0)x10^-3, where the uncertainties are statistical and systematic respectively. By using Heavy Quark Effective Theory calculations for F(1), a value of |Vcb| = (40.7+-1.1+-2.2+-1.6)x 10^-3 was obtained, where the third error is due to theoretical uncertainties in the value of F(1). The branching ratio Br(B0 to D* l nu) was also measured to be (5.26+-0.20+-0.46) The magnitude of the Cabibbo-Kobayashi-Maskawa matrix element V cb has been measured using B ̄ 0 → D ∗+ ℓ − ν ̄ decays recorded on the Z 0 peak using the OPAL detector at LEP. The D ∗+ → D 0 π + decays were reconstructed both in the particular decay modes D 0 →K − π + and D 0 →K − π + π 0 and via an inclusive technique. The product of | V cb | and the decay form factor of the B ̄ 0 → D ∗+ ℓ − ν ̄ transition at zero recoil F (1) was measured to be F (1)|V cb |=(37.1±1.0±2.0)×10 −3 , where the uncertainties are statistical and systematic respectively. By using Heavy Quark Effective Theory calculations for F (1) , a value of |V cb |=(40.7±1.1±2.2±1.6)×10 −3 was obtained, where the third error is due to theoretical uncertainties in the value of F (1) . The branching ratio Br( B ̄ 0 →D ∗+ ℓ − ν ̄ ) was also measured to be (5.26±0.20±0.46)%. The magnitude of the Cabibbo-Kobayashi-Maskawa matrix element Vcb has been measured using B0 to D*l nu decays recorded on the Z0 peak using the OPAL detector at LEP. The D* to D0 pi+ decays were reconstructed both in the particular decay modes D0 to K- pi+ and D0 to K- pi+ pi- and via an inclusive technique. The product of |Vcb| and the decay form factor of the B0 to D* l nu transition at zero recoil F(1) was measured to be F(1)|Vcb| = (37.1+-1.0+-2.0)x10^-3, where the uncertainties are statistical and systematic respectively. By using Heavy Quark Effective Theory calculations for F(1), a value of |Vcb| = (40.7+-1.1+-2.2+-1.6)x 10^-3 was obtained, where the third error is due to theoretical uncertainties in the value of F(1). The branching ratio Br(B0 to D* l nu) was also measured to be (5.26+-0.20+-0.46)%.

Published
2000

207. QCD studies with e+e- annihilation data at 172-189 GeV

Author

Abbiendi, G., Ackerstaff, K., Akesson, P.F., Alexander, G., Allison, John, Anderson, K.J., Arcelli, S., Asai, S., Ashby, S.F., Axen, D., Azuelos, G., Bailey, I., Ball, A.H., Barberio, E., Barlow, Roger J., Batley, J.R., Baumann, S., Behnke, T., Bell, Kenneth Watson, Bella, G., Bellerive, A., Bentvelsen, S., Bethke, S., Biebel, O., Biguzzi, A., Bloodworth, I.J., Bock, P., Bohme, J., Boeriu, O., Bonacorsi, D., Boutemeur, M., Braibant, S., Bright-Thomas, P., Brigliadori, L., Brown, Robert M., Burckhart, H.J., Cammin, J., Capiluppi, P., Carnegie, R.K., Carter, A.A., Carter, J.R., Chang, C.Y., Charlton, David G., Chrisman, D., Ciocca, C., Clarke, P.E.L., Clay, E., Cohen, I., Cooke, O.C., Couchman, J., Couyoumtzelis, C., Coxe, R.L., Cuffiani, M., Dado, S., Dallavalle, G.Marco, Dallison, S., Davis, R., de Roeck, A., Dervan, P., Desch, K., Dienes, B., Dixit, M.S., Donkers, M., Dubbert, J., Duchovni, E., Duckeck, G., Duerdoth, I.P., Estabrooks, P.G., Etzion, E., Fabbri, F., Fanfani, A., Fanti, M., Faust, A.A., Feld, L., Ferrari, P., Fiedler, F., Fierro, M., Fleck, I., Frey, A., Furtjes, A., Futyan, D.I., Gagnon, P., Gary, J.W., Gaycken, G., Geich-Gimbel, C., Giacomelli, G., Giacomelli, P., Gingrich, D.M., Glenzinski, D., Goldberg, J., Gorn, W., Grandi, C., Graham, K., Gross, E., Grunhaus, J., Gruwe, M., Gunther, P.O., Hajdu, C., Hanson, G.G., Hansroul, M., Hapke, M., Harder, K., Harel, A., Hargrove, C.K., Harin-Dirac, M., Hauke, A., Hauschild, M., Hawkes, C.M., Hawkings, R., Hemingway, R.J., Hensel, C., Herten, G., Heuer, R.D., Hildreth, M.D., Hill, J.C., Hobson, P.R., Hocker, James Andrew, Hoffman, Kara Dion, Homer, R.J., Honma, A.K., Horvath, D., Hossain, K.R., Howard, R., Huntemeyer, P., Igo-Kemenes, P., Imrie, D.C., Ishii, K., Jacob, F.R., Jawahery, A., Jeremie, H., Jimack, M., Jones, C.R., Jovanovic, P., Junk, T.R., Kanaya, N., Kanzaki, J., Karapetian, G., Karlen, D., Kartvelishvili, V., Kawagoe, K., Kawamoto, T., Kayal, P.I., Keeler, R.K., Kellogg, R.G., Kennedy, B.W., Kim, D.H., Klein, K., Klier, A., Kobayashi, T., Kobel, M., Kokott, T.P., Kolrep, M., Komamiya, S., Kowalewski, Robert V., Kress, T., Krieger, P., von Krogh, J., Kuhl, T., Kupper, M., Kyberd, P., Lafferty, G.D., Landsman, H., Lanske, D., Lawson, I., Layter, J.G., Leins, A., Lellouch, D., Letts, J., Levinson, L., Liebisch, R., Lillich, J., List, B., Littlewood, C., Lloyd, A.W., Lloyd, S.L., Loebinger, F.K., Long, G.D., Losty, M.J., Lu, J., Ludwig, J., Macchiolo, A., Macpherson, A., Mader, W., Mannelli, M., Marcellini, S., Marchant, T.E., Martin, A.J., Martin, J.P., Martinez, G., Mashimo, T., Mattig, Peter, McDonald, W.John, McKenna, J., McMahon, T.J., McPherson, R.A., Meijers, F., Mendez-Lorenzo, P., Merritt, F.S., Mes, H., Meyer, I., Michelini, A., Mihara, S., Mikenberg, G., Miller, D.J., Mohr, W., Montanari, A., Mori, T., Nagai, K., Nakamura, I., Neal, H.A., Nisius, R., O'Neale, S.W., Oakham, F.G., Odorici, F., Ogren, H.O., Okpara, A., Oreglia, M.J., Orito, S., Pasztor, G., Pater, J.R., Patrick, G.N., Patt, J., Perez-Ochoa, R., Pfeifenschneider, P., Pilcher, J.E., Pinfold, J., Plane, David E., Poli, B., Polok, J., Przybycien, M., Quadt, A., Rembser, C., Rick, H., Robins, S.A., Rodning, N., Roney, J.M., Rosati, S., Roscoe, K., Rossi, A.M., Rozen, Y., Runge, K., Runolfsson, O., Rust, D.R., Sachs, K., Saeki, T., Sahr, O., Sang, W.M., Sarkisian, E.K.G., Sbarra, C., Schaile, A.D., Schaile, O., Scharff-Hansen, P., Schmitt, S., Schoning, A., Schroder, Matthias, Schumacher, M., Schwick, C., Scott, W.G., Seuster, R., Shears, T.G., Shen, B.C., Shepherd-Themistocleous, C.H., Sherwood, P., Siroli, G.P., Skuja, A., Smith, A.M., Snow, G.A., Sobie, R., Soldner-Rembold, S., Spagnolo, S., Sproston, M., Stahl, A., Stephens, K., Stoll, K., Strom, David M., Strohmer, R., Surrow, B., Talbot, S.D., Tarem, S., Taylor, R.J., Teuscher, R., Thiergen, M., Thomas, J., Thomson, M.A., Torrence, E., Towers, S., Trefzger, T., Trigger, I., Trocsanyi, Z., Tsur, E., Turner-Watson, M.F., Ueda, I., Van Kooten, Rick J., Vannerem, P., Verzocchi, M., Voss, H., Waller, D., Ward, C.P., Ward, D.R., Watkins, P.M., Watson, A.T., Watson, N.K., Wells, P.S., Wengler, T., Wermes, N., Wetterling, D., White, J.S., Wilson, G.W., Wilson, J.A., Wyatt, T.R., Yamashita, S., Zacek, V., Zer-Zion, D., G., Abbiendi, K., Ackerstaff, P. F., Akesson, G., Alexander, J., Allison, K. J., Anderson, S., Arcelli, S., Asai, S. F., Ashby, D., Axen, G., Azuelo, I., Bailey, A. H., Ball, E., Barberio, R. J., Barlow, J. R., Batley, S., Baumann, T., Behnke, K. W., Bell, G., Bella, A., Bellerive, S., Bentvelsen, S., Bethke, O., Biebel, A., Biguzzi, I. J., Bloodworth, P., Bock, J., Bohme, O., Boeriu, D., Bonacrosi, M., Boutemeur, S., Braibant, P., Bright Thoma, L., Brigliadori, R. M., Brown, H. J., Burckhart, J., Cammin, P., Capiluppi, R. K., Carnegie, A. A., Carter, J. R., Carter, C. Y., Chang, D. G., Charlton, D., Chrisman, C., Ciocca, P. E., L., E., Clay, I., Cohen, O. C., Cooke, J., Couchman, C., Couyoumtzeli, R. L., Coxe, M., Cuffiani, S., Dado, G. M., Dallavalle, S., Dallison, R., Davi, A., de Roeck, P., Dervan, K., Desch, B., Diene, M. S., Dixit, M., Donker, J., Dubbert, E., Duchovni, G., Duckeck, I. P., Duerdoth, P. G., Estabrook, E., Etzion, F., Fabbri, A., Fanfani, M., Fanti, A. A., Faust, L., Feld, P., Ferrari, F., Fiedler, M., Fierro, I., Fleck, A., Frey, A., Furtje, D. I., Futyan, P., Gagnon, J. W., Gary, G., Gaycken, C., Geich Gimbel, G., Giacomelli, P., Giacomelli, D. M., Gingrich, D., Glenzinski, J., Goldberg, W., Gorn, C., Grandi, K., Graham, E., Gro, J., Grunhau, M., Gruwe, P. O., Gunther, C., Hajdu, G. G., Hanson, M., Hansroul, M., Hapke, K., Harder, A., Harel, C. K., Hargrove, M., Harin Dirac, A., Hauke, M., Hauschild, C. M., Hawke, R., Hawking, R. J., Hemingway, C., Hensel, G., Herten, R. D., Heuer, M. D., Hildreth, J. C., Hill, P. R., Hobson, A., Hocker, K., Hoffman, R. J., Homer, A. K., Honma, D., Horvath, K. R., Hossain, R., Howard, P., Huntemeyer, P., Igo Kemene, D. C., Imrie, K., Ishii, F. R., Jacob, A., Jawahery, H., Jeremie, M., Jimack, C. R., Jone, P., Jovanovic, T. R., Junk, N., Kanaya, J., Kanzaki, G., Karapetian, D., Karlen, V., Kartvelishvili, K., Kawagoe, T., Kawamoto, P. I., Kayal, R. K., Keeler, R. G., Kellogg, B. W., Kennedy, D. H., Kim, K., Klein, A., Klier, T., Kobayashi, M., Kobel, T. P., Kokott, M., Kolrep, S., Komamiya, R. V., Kowalewski, T., Kre, P., Krieger, J., von Krogh, T., Kuhl, M., Kupper, P., Kyberd, G. D., Lafferty, H., Landsman, D., Lanske, I., Lawson, J. G., Layter, A., Lein, D., Lellouch, J., Lett, L., Levinson, R., Liebisch, J., Lillich, B., List, C., Littlewood, A. W., Lloyd, S. L., Lloyd, F. K., Loebinger, G. D., Long, M. J., Losty, J., Lu, J., Ludwig, A., Macchiolo, A., Macpherson, W., Mader, M., Mannelli, S., Marcellini, T. E., Marchant, A. J., Martin, J. P., Martin, G., Martinez, T., Mashimo, P., Mattig, W. J., Mcdonald, J., Mckenna, T. J., Mcmahon, R. A., Mcpherson, F., Meijer, P., Mendez Lorenzo, F. S., Merritt, H., Me, I., Meyer, A., Michelini, S., Mihara, G., Mikenberg, D. J., Miller, W., Mohr, A., Montanari, T., Mori, K., Nagai, I., Nakamura, H. A., Neal, R., Nisiu, S. W., O'Neale, F. G., Oakham, F., Odorici, H. O., Ogren, A., Okpara, M. J., Oreglia, S., Orito, G., Pasztor, J. R., Pater, G. N., Patrick, J., Patt, R., Perez Ochoa, P., Pfeifenschneider, J. E., Pilcher, J., Pinfold, D. E., Plane, B., Poli, J., Polok, M., Przybycien, A., Quadt, C., Rembser, H., Rick, S. A., Robin, N., Rodning, J. M., Roney, S., Rosati, K., Roscoe, A. M., Rossi, Y., Rozen, K., Runge, O., Runolfsson, D. R., Rust, K., Sach, T., Saeki, O., Sahr, W. M., Sang, E. K., G., C., Sbarra, A. D., Schaile, O., Schaile, P., Scharff Hansen, S., Schmitt, A., Schoning, M., Schroder, M., Schumacher, C., Schwick, W. G., Scott, R., Seuster, T. G., Shear, B. C., Shen, C. H., Shepherd Themistocleou, P., Sherwood, G. P., Siroli, A., Skuja, A. M., Smith, G. A., Snow, R., Sobie, S., Soldner Rembold, Spagnolo, Stefania Antonia, M., Sproston, A., Stahl, K., Stephen, K., Stoll, D., Strom, R., Strohmer, B., Surrow, S. D., Talbot, S., Tarem, R. J., Taylor, R., Teuscher, M., Thiergen, J., Thoma, M. A., Thomson, E., Torrence, S., Tower, T., Trefzger, I., Trigger, Z., Trocsanyi, E., Tsur, M. F., Turner Watson, I., Ueda, R., Van Kooten, P., Vannerem, M., Verzocchi, H., Vo, D., Waller, C. P., Ward, D. R., Ward, P. M., Watkin, A. T., Watson, N. K., Watson, P. S., Well, T., Wengler, N., Werme, D., Wetterling, J. S., White, G. W., Wilson, J. A., Wilson, T. R., Wyatt, S., Yamashita, V., Zacek, and D., Zer Zion

Subjects
Quantum chromodynamics, Physics, Particle physics, Annihilation, Physics and Astronomy (miscellaneous), 010308 nuclear & particles physics, Hadron, Monte Carlo method, FOS: Physical sciences, 01 natural sciences, Charged particle, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, Strong coupling, High Energy Physics::Experiment, Multiplicity (chemistry), 010306 general physics, Engineering (miscellaneous), Particle Physics - Experiment
Abstract

We have studied hadronic events from e+e- annihilation data at centre-of-mass energies of sqrt{s}=172, 183 and 189 GeV. The total integrated luminosity of the three samples, measured with the OPAL detector, corresponds to 250 pb^-1. We present distributions of event shape variables, charged particle multiplicity and momentum, measured separately in the three data samples. From these we extract measurements of the strong coupling alpha_s, the mean charged particle multiplicity and the peak position xi_0 in the xi_p=ln(1/x_p) distribution. In general the data are described well by analytic QCD calculations and Monte Carlo models. Our measured values of alpha_s, and xi_0 are consistent with previous determinations at sqrt{s}=MZ., Comment: 49 pages, 13 figures, submitted to Eur. Phys. J. C

Published
2000

208. De Echtheid van Big Brother

Author

Fennema, M., van Dullemen, C., Costera Meyer, I., Reesink, M., Rethinking politics, transnational society, network interaction and democratic governance (ASSR, FMG), and IMES (FMG)

Published
2000

209. Transverse and longitudinal Bose-Einstein correlations in hadronic Z(0) decays

Author

Abbiendi, G., Ackerstaff, K., Akesson, P. F., Alexander, G., Allison, J., Anderson, K. J., Arcelli, S., Asai, S., Ashby, S. F., Axen, D., Azuelos, G., Bailey, I., Ball, A. H., Barberio, E., Barlow, R. J., Batley, J. R., Baumann, S., Behnke, T., Bell, K. W., Bella, G., Bellerive, A., Bentvelsen, S., Bethke, S., Biebel, O., Biguzzi, A., Bloodworth, I. J., Bock, P., Bohme, J., Boeriu, O., Bonacorsi, D., Boutemeur, M., Braibant, S., Bright-Thomas, P., Brigliadori, L., Brown, R. M., Burckhart, H. J., Cammin, J., Capiluppi, P., Carnegie, R. K., Carter, A. A., Carter, J. R., Chang, C. Y., Charlton, D. G., Chrisman, D., Ciocca, C., Clarke, P. E. L., Clay, E., Cohen, I., Cooke, O. C., Couchman, J., Couyoumtzelis, C., Coxe, R. L., Cuffiani, M., Dado, S., Dallavalle, G. M., Dallison, S., Davis, R., Roeck, A., Dervan, P., Desch, K., Dienes, B., Dixit, M. S., Donkers, M., Dubbert, J., Duchovni, E., Duckeck, G., Duerdoth, I. P., Estabrooks, P. G., Etzion, E., Fabbri, F., Fanfani, A., Fanti, M., Faust, A. A., Feld, L., Ferrari, P., Fiedler, F., Fierro, M., Fleck, I., Frey, A., Furtjes, A., Futyan, D. I., Gagnon, P., Gary, J. W., Gaycken, G., Geich-Gimbel, C., Giacomelli, G., Giacomelli, P., Gingrich, D. M., Glenzinski, D., Goldberg, J., Gorn, W., Grandi, C., Graham, K., Gross, E., Grunhaus, J., Gruwe, M., Gunther, P. O., Hajdu, C., Hanson, G. G., Hansroul, M., Hapke, M., Harder, K., Harel, A., Hargrove, C. K., Harin-Dirac, M., Hauke, A., Hauschild, M., Hawkes, C. M., Hawkings, R., Hemingway, R. J., Hensel, C., Herten, G., Heuer, R. D., Hildreth, M. D., Hill, J. C., Hobson, P. R., Hocker, A., Hoffman, K., Homer, R. J., Honma, A. K., Horvath, D., Hossain, K. R., Howard, R., Huntemeyer, P., Igo-Kemenes, P., Imrie, D. C., Ishii, K., Jacob, F. R., Jawahery, A., Jeremie, H., Jimack, M., Jones, C. R., Jovanovic, P., Junk, T. R., Kanaya, N., Kanzaki, J., Karapetian, G., Karlen, D., Kartvelishvili, V., Kawagoe, K., Kawamoto, T., Kayal, P. I., Keeler, R. K., Kellogg, R. G., Kennedy, B. W., Kim, D. H., Klein, K., Klier, A., Kobayashi, T., Kobel, M., Kokott, T. P., Kolrep, M., Komamiya, S., Kowalewski, R. V., Kress, T., Krieger, P., Krogh, J., Kuhl, T., Kupper, M., Kyberd, P., Lafferty, G. D., Landsman, H., Lanske, D., Lawson, I., Layter, J. G., Leins, A., Lellouch, D., Letts, J., Levinson, L., Liebisch, R., Lillich, J., List, B., Littlewood, C., Lloyd, A. W., Lloyd, S. L., Loebinger, F. K., Long, G. D., Losty, M. J., Lu, J., Ludwig, J., Macchiolo, A., Macpherson, A., Mader, W., Mannelli, M., Marcellini, S., Marchant, T. E., Martin, A. J., Martin, J. P., Martinez, G., Mashimo, T., Mattig, P., Mcdonald, W. J., Mckenna, J., Mcmahon, T. J., Mcpherson, R. A., Meijers, F., Mendez-Lorenzo, P., Merritt, F. S., Mes, H., Meyer, I., Michelini, A., Mihara, S., Mikenberg, G., Miller, D. J., Mohr, W., Montanari, A., Mori, T., Nagai, K., Nakamura, I., Neal, H. A., Nisius, R., O Neale, S. W., Oakham, F. G., Odorici, F., Ogren, H. O., Okpara, A., Oreglia, M. J., Orito, S., Pasztor, G., Pater, J. R., Patrick, G. N., Patt, J., Perez-Ochoa, R., Pfeifenschneider, P., Pilcher, J. E., Pinfold, J., Plane, D. E., Poli, B., Polok, J., Przybycien, M., Quadt, A., Rembser, C., Rick, H., Robins, S. A., Rodning, N., Roney, J. M., Rosati, S., Roscoe, K., Rossi, A. M., Rozen, Y., Runge, K., Runolfsson, O., Rust, D. R., Sachs, K., Saeki, T., Sahr, O., Sang, W. M., Sarkisyan, E. K. G., Sbarra, C., Schaile, A. D., Schaile, O., Scharff-Hansen, P., Schmitt, S., Schoning, A., Schroder, M., Schumacher, M., Schwick, C., Scott, W. G., Seuster, R., Shears, T. G., Shen, B. C., Shepherd-Themistocleous, C. H., Sherwood, P., Siroli, G. P., Skuja, A., Smith, A. M., Snow, G. A., Sobie, R., Soldner-Rembold, S., stefania spagnolo, Sproston, M., Stahl, A., Stephens, K., Stoll, K., Strom, D., Strohmer, R., Surrow, B., Talbot, S. D., Tarem, S., Taylor, R. J., Teuscher, R., Thiergen, M., Thomas, J., Thomson, M. A., Torrence, E., Towers, S., Trefzger, T., Trigger, I., Trocsanyi, Z., Tsur, E., Turner-Watson, M. F., Ueda, I., Kooten, R., Vannerem, P., Verzocchi, M., Voss, H., Waller, D., Ward, C. P., Ward, D. R., Watkins, P. M., Watson, A. T., Watson, N. K., Wells, P. S., Wengler, T., Wermes, N., Wetterling, D., White, J. S., Wilson, G. W., Wilson, J. A., Wyatt, T. R., Yamashita, S., Zacek, V., Zer-Zion, D., Opal Collaboration, G., Abbiendi, K., Ackerstaff, P. F., Akesson, G., Alexander, J., Allison, K. J., Anderson, S., Arcelli, S., Asai, S. F., Ashby, D., Axen, G., Azuelo, I., Bailey, A. H., Ball, E., Barberio, R. J., Barlow, J. R., Batley, S., Baumann, T., Behnke, K. W., Bell, G., Bella, A., Bellerive, S., Bentvelsen, S., Bethke, O., Biebel, A., Biguzzi, I. J., Bloodworth, P., Bock, J., Bohme, O., Boeriu, D., Bonacorsi, M., Boutemeur, S., Braibant, P., Bright Thoma, L., Brigliadori, R. M., Brown, H. J., Burckhart, J., Cammin, P., Capiluppi, R. K., Carnegie, A. A., Carter, J. R., Carter, C. Y., Chang, D. G., Charlton, D., Chrisman, C., Ciocca, P. E., L., E., Clay, I., Cohen, O. C., Cooke, J., Couchman, C., Couyoumtzeli, R. L., Coxe, M., Cuffiani, S., Dado, G. M., Dallavalle, S., Dallison, R., Davi, A., de Roeck, P., Dervan, K., Desch, B., Diene, M. S., Dixit, M., Donker, J., Dubbert, E., Duchovni, G., Duckeck, I. P., Duerdoth, P. G., Estabrook, E., Etzion, F., Fabbri, A., Fanfani, M., Fanti, A. A., Faust, L., Feld, P., Ferrari, F., Fiedler, M., Fierro, I., Fleck, A., Frey, A., Furtje, D. I., Futyan, P., Gagnon, J. W., Gary, G., Gaycken, C., Geich Gimbel, G., Giacomelli, P., Giacomelli, D. M., Gingrich, D., Glenzinski, J., Goldberg, W., Gorn, C., Grandi, K., Graham, E., Gro, J., Grunhau, M., Gruwe, P. O., Gunther, C., Hajdu, G. G., Hanson, M., Hansroul, M., Hapke, K., Harder, A., Harel, C. K., Hargrove, M., Harin Dirac, A., Hauke, M., Hauschild, C. M., Hawke, R., Hawking, R. J., Hemingway, C., Hensel, G., Herten, R. D., Heuer, M. D., Hildreth, J. C., Hill, P. R., Hobson, A., Hocker, K., Hoffman, R. J., Homer, A. K., Honma, D., Horvath, K. R., Hossain, R., Howard, P., Huntemeyer, P., Igo Kemene, D. C., Imrie, K., Ishii, F. R., Jacob, A., Jawahery, H., Jeremie, M., Jimack, C. R., Jone, P., Jovanovic, T. R., Junk, N., Kanaya, J., Kanzaki, G., Karapetian, D., Karlen, V., Kartvelishvili, K., Kawagoe, T., Kawamoto, P. I., Kayal, R. K., Keeler, R. G., Kellogg, B. W., Kennedy, D. H., Kim, K., Klein, A., Klier, T., Kobayashi, M., Kobel, T. P., Kokott, M., Kolrep, S., Komamiya, R. V., Kowalewski, T., Kre, P., Krieger, J., von Krogh, T., Kuhl, M., Kupper, P., Kyberd, G. D., Lafferty, H., Landsman, D., Lanske, I., Lawson, J. G., Layter, A., Lein, D., Lellouch, J., Lett, L., Levinson, R., Liebisch, J., Lillich, B., List, C., Littlewood, A. W., Lloyd, S. L., Lloyd, F. K., Loebinger, G. D., Long, M. J., Losty, J., Lu, J., Ludwig, A., Macchiolo, A., Macpherson, W., Mader, M., Mannelli, S., Marcellini, T. E., Marchant, A. J., Martin, J. P., Martin, G., Martinez, T., Mashimo, P., Mattig, W. J., Mcdonald, J., Mckenna, T. J., Mcmahon, R. A., Mcpherson, F., Meijer, P., Mendez Lorenzo, F. S., Merritt, H., Me, I., Meyer, A., Michelini, S., Mihara, G., Mikenberg, D. J., Miller, W., Mohr, A., Montanari, T., Mori, K., Nagai, I., Nakamura, H. A., Neal, R., Nisiu, S. W., O'Neale, F. G., Oakham, F., Odorici, H. O., Ogren, A., Okpara, M. J., Oreglia, S., Orito, G., Pasztor, J. R., Pater, G. N., Patrick, J., Patt, R., Perez Ochoa, P., Pfeifenschneider, J. E., Pilcher, J., Pinfold, D. E., Plane, B., Poli, J., Polok, M., Przybycien, A., Quadt, C., Rembser, H., Rick, S. A., Robin, N., Rodning, J. M., Roney, S., Rosati, K., Roscoe, A. M., Rossi, Y., Rozen, K., Runge, O., Runolfsson, D. R., Rust, K., Sach, T., Saeki, O., Sahr, W. M., Sang, E. K., G., C., Sbarra, A. D., Schaile, O., Schaile, P., Scharff Hansen, S., Schmitt, A., Schoning, M., Schroder, M., Schumacher, C., Schwick, W. G., Scott, R., Seuster, T. G., Shear, B. C., Shen, C. H., Shepherd Themistocleou, P., Sherwood, G. P., Siroli, A., Skuja, A. M., Smith, G. A., Snow, R., Sobie, S., Soldner Rembold, Spagnolo, Stefania Antonia, M., Sproston, A., Stahl, K., Stephen, K., Stoll, D., Strom, R., Strohmer, B., Surrow, S. D., Talbot, S., Tarem, R. J., Taylor, R., Teuscher, M., Thiergen, J., Thoma, M. A., Thomson, E., Torrence, S., Tower, T., Trefzger, I., Trigger, Z., Trocsanyi, E., Tsur, M. F., Turner Watson, I., Ueda, R., Van Kooten, P., Vannerem, M., Verzocchi, H., Vo, D., Waller, C. P., Ward, D. R., Ward, P. M., Watkin, A. T., Watson, N. K., Watson, P. S., Well, T., Wengler, N., Werme, D., Wetterling, J. S., White, G. W., Wilson, J. A., Wilson, T. R., Wyatt, S., Yamashita, V., Zacek, and D., Zer Zion

Published
2000

210. The 7-13 March 2006 major Saharan outbreak: Multiproxy characterization of mineral dust deposited on the West African margin

Author

Skonieczny, C., Bory, A., Bout-Roumazeilles, V., Abouchami, W., Galer, S.J.G., Crosta, X., Stuut, J.B., Meyer, I., Chiapello, I., Podvin, T., Chatenet, B., Diallo, A., Ndiaye, T., Skonieczny, C., Bory, A., Bout-Roumazeilles, V., Abouchami, W., Galer, S.J.G., Crosta, X., Stuut, J.B., Meyer, I., Chiapello, I., Podvin, T., Chatenet, B., Diallo, A., and Ndiaye, T.

Abstract

Mineral dust deposits were collected at Mbour, Senegal, throughout the spring of 2006 and especially during the well-documented March 7-13 large Saharan dust outbreak. During this 7-day period, significant changes in mass flux, grain-size, clay mineralogy and Sr and Nd isotopic compositions were recorded, indicating distinct provenances for the dust transported and deposited during and outside the event. All these terrigenous proxies, as well as freshwater diatom taxa, also showed significant temporal variations during the outbreak, implying contributions from at least two different provenance regions. Tri-dimensional back-trajectories and satellite imaging enabled us to link those distinct signatures to regions increasingly to the southeast within a large area covering Mauritania, Mali and southern Algeria, identified by the Total Ozone Mapping Spectrometer (TOMS) as the main source of the prominent winter/spring plume over the tropical Atlantic. The multiproxy characterization of the March 7-13 dust fall therefore enables us to typify the terrigenous signature of two different regions supplying dust off West Africa, and provide valuable clues for the interpretation of Northeastern Tropical Atlantic Ocean dust sedimentary records in terms of changes in provenance regions and transport systems. Additionally, because dust deposition data are scarce, flux and grain size data obtained in this study, among other parameters such as clay assemblages, provide important constraints for atmospheric transport models and dust deposition budget estimates in this area.

Published
2011

211. Bose-Einstein correlations in $K^{\pm}K^{\pm}$ pairs from $Z^{0}$ decays into two hadronic jets

Author

Abbiendi, G., Ackerstaff, K., Akesson, P.F., Alexander, G., Allison, John, Anderson, K.J., Arcelli, S., Asai, S., Ashby, S.F., Axen, D., Azuelos, G., Bailey, I., Ball, A.H., Barberio, E., Barlow, Roger J., Batley, J.R., Baumann, S., Behnke, T., Bell, Kenneth Watson, Bella, G., Bellerive, A., Bentvelsen, S., Bethke, S., Betts, S., Biebel, O., Biguzzi, A., Bloodworth, I.J., Bock, P., Bohme, J., Boeriu, O., Bonacorsi, D., Boutemeur, M., Braibant, S., Bright-Thomas, P., Brigliadori, L., Brown, Robert M., Burckhart, H.J., Capiluppi, P., Carnegie, R.K., Carter, A.A., Carter, J.R., Chang, C.Y., Charlton, David G., Chrisman, D., Ciocca, C., Clarke, P.E.L., Clay, E., Cohen, I., Conboy, J.E., Cooke, O.C., Couchman, J., Couyoumtzelis, C., Coxe, R.L., Cuffiani, M., Dado, S., Dallavalle, G.Marco, Dallison, S., Davis, R., de Roeck, A., Dervan, P., Desch, K., Dienes, B., Dixit, M.S., Donkers, M., Dubbert, J., Duchovni, E., Duckeck, G., Duerdoth, I.P., Estabrooks, P.G., Etzion, E., Fabbri, F., Fanfani, A., Fanti, M., Faust, A.A., Feld, L., Ferrari, P., Fiedler, F., Fierro, M., Fleck, I., Frey, A., Furtjes, A., Futyan, D.I., Gagnon, P., Gary, J.W., Gaycken, G., Geich-Gimbel, C., Giacomelli, G., Giacomelli, P., Gingrich, D.M., Glenzinski, D., Goldberg, J., Gorn, W., Grandi, C., Graham, K., Gross, E., Grunhaus, J., Gruwe, M., Hajdu, C., Hanson, G.G., Hansroul, M., Hapke, M., Harder, K., Harel, A., Hargrove, C.K., Harin-Dirac, M., Hauschild, M., Hawkes, C.M., Hawkings, R., Hemingway, R.J., Herten, G., Heuer, R.D., Hildreth, M.D., Hill, J.C., Hobson, P.R., Hocker, James Andrew, Hoffman, Kara Dion, Homer, R.J., Honma, A.K., Horvath, D., Hossain, K.R., Howard, R., Huntemeyer, P., Igo-Kemenes, P., Imrie, D.C., Ishii, K., Jacob, F.R., Jawahery, A., Jeremie, H., Jimack, M., Jones, C.R., Jovanovic, P., Junk, T.R., Kanaya, N., Kanzaki, J., Karapetian, G., Karlen, D., Kartvelishvili, V., Kawagoe, K., Kawamoto, T., Kayal, P.I., Keeler, R.K., Kellogg, R.G., Kennedy, B.W., Kim, D.H., Klier, A., Kobayashi, T., Kobel, M., Kokott, T.P., Kolrep, M., Komamiya, S., Kowalewski, Robert V., Kress, T., Krieger, P., von Krogh, J., Kuhl, T., Kupper, M., Kyberd, P., Lafferty, G.D., Landsman, H., Lanske, D., Lauber, J., Lawson, I., Layter, J.G., Lellouch, D., Letts, J., Levinson, L., Liebisch, R., Lillich, J., List, B., Littlewood, C., Lloyd, A.W., Lloyd, S.L., Loebinger, F.K., Long, G.D., Losty, M.J., Lu, J., Ludwig, J., Macchiolo, A., Macpherson, A., Mader, W., Mannelli, M., Marcellini, S., Marchant, T.E., Martin, A.J., Martin, J.P., Martinez, G., Mashimo, T., Mattig, Peter, McDonald, W.John, McKenna, J., Mckigney, E.A., McMahon, T.J., McPherson, R.A., Meijers, F., Mendez-Lorenzo, P., Merritt, F.S., Mes, H., Meyer, I., Michelini, A., Mihara, S., Mikenberg, G., Miller, D.J., Mohr, W., Montanari, A., Mori, T., Nagai, K., Nakamura, I., Neal, H.A., Nisius, R., O'Neale, S.W., Oakham, F.G., Odorici, F., Ogren, H.O., Okpara, A., Oreglia, M.J., Orito, S., Pasztor, G., Pater, J.R., Patrick, G.N., Patt, J., Perez-Ochoa, R., Petzold, S., Pfeifenschneider, P., Pilcher, J.E., Pinfold, J., Plane, David E., Poli, B., Polok, J., Przybycien, M., Quadt, A., Rembser, C., Rick, H., Robins, S.A., Rodning, N., Roney, J.M., Rosati, S., Roscoe, K., Rossi, A.M., Rozen, Y., Runge, K., Runolfsson, O., Rust, D.R., Sachs, K., Saeki, T., Sahr, O., Sang, W.M., Sarkisian, E.K.G., Sbarra, C., Schaile, A.D., Schaile, O., Scharff-Hansen, P., Schieck, J., Schmitt, S., Schoning, A., Schroder, Matthias, Schumacher, M., Schwick, C., Scott, W.G., Seuster, R., Shears, T.G., Shen, B.C., Shepherd-Themistocleous, C.H., Sherwood, P., Siroli, G.P., Skuja, A., Smith, A.M., Snow, G.A., Sobie, R., Soldner-Rembold, S., Spagnolo, S., Sproston, M., Stahl, A., Stephens, K., Stoll, K., Strom, David M., Strohmer, R., Surrow, B., Talbot, S.D., Taras, P., Tarem, S., Teuscher, R., Thiergen, M., Thomas, J., Thomson, M.A., Torrence, E., Towers, S., Trefzger, T., Trigger, I., Trocsanyi, Z., Tsur, E., Turner-Watson, M.F., Ueda, I., Van Kooten, Rick J., Vannerem, P., Verzocchi, M., Voss, H., Wackerle, F., Waller, D., Ward, C.P., Ward, D.R., Watkins, P.M., Watson, A.T., Watson, N.K., Wells, P.S., Wengler, T., Wermes, N., Wetterling, D., White, J.S., Wilson, G.W., Wilson, J.A., Wyatt, T.R., Yamashita, S., Zacek, V., and Zer-Zion, D.

Subjects
High Energy Physics::Experiment, Astrophysics::Earth and Planetary Astrophysics, Particle Physics - Experiment
Abstract

Bose-Einstein correlations in pairs of charged kaons produced in a sample of 3.9 million hadronic Z0 decays have been measured with the OPAL experiment at LEP. Charged kaons were identified in the central tracking detector using their specific energy loss in the drift chamber gas. The correlation function was studied in two-jet events using a double ratio, formed by the number of like-sign pairs normalised by a reference sample in the data, divided by the same ratio in a Monte Carlo simulation. The enhancement at small values of the four-momentum difference of the pair was parametrised using a Gaussian function. The parameters of the Bose-Einstein correlations were measured to be lambda = 0.82+-0.22(+0.17,-0.12) for the strength and R0 = 0.56+-0.08(+0.08, -0.06) fm for the kaon source radius, where the first errors are statistical and the second systematic. Corrections for final-state interactions are discussed. Bose-Einstein correlations in pairs of charged kaons produced in a sample of 3.9 million hadronic Z0 decays have been measured with the OPAL experiment at LEP. Charged kaons were identified in the central tracking detector using their specific energy loss in the drift chamber gas. The correlation function was studied in two-jet events using a double ratio, formed by the number of like-sign pairs normalised by a reference sample in the data, divided by the same ratio in a Monte Carlo simulation. The enhancement at small values of the four-momentum difference of the pair was parametrised using a Gaussian function. The parameters of the Bose-Einstein correlations were measured to be lambda = 0.82+-0.22(+0.17,-0.12) for the strength and R0 = 0.56+-0.08(+0.08,-0.06) fm for the kaon source radius, where the first errors are statistical and the second systematic. Corrections for final-state interactions are discussed.

Published
1999

212. Search for Chargino and Neutralino Production at $\sqrt{s} = 189 GeV$ at LEP

Author

Abbiendi, G., Ackerstaff, K., Alexander, G., Allison, John, Anderson, K.J., Anderson, S., Arcelli, S., Asai, S., Ashby, S.F., Axen, D., Azuelos, G., Ball, A.H., Barberio, E., Barlow, Roger J., Batley, J.R., Baumann, S., Bechtluft, J., Behnke, T., Bell, Kenneth Watson, Bella, G., Bellerive, A., Bentvelsen, S., Bethke, S., Betts, S., Biebel, O., Biguzzi, A., Bloodworth, I.J., Bock, P., Bohme, J., Boeriu, O., Bonacorsi, D., Boutemeur, M., Braibant, S., Bright-Thomas, P., Brigliadori, L., Brown, Robert M., Burckhart, H.J., Capiluppi, P., Carnegie, R.K., Carter, A.A., Carter, J.R., Chang, C.Y., Charlton, David G., Chrisman, D., Ciocca, C., Clarke, P.E.L., Clay, E., Cohen, I., Conboy, J.E., Cooke, O.C., Couchman, J., Couyoumtzelis, C., Coxe, R.L., Cuffiani, M., Dado, S., Dallavalle, G.Marco, Dallison, S., Davis, R., De Jong, S., de Roeck, A., Dervan, P., Desch, K., Dienes, B., Dixit, M.S., Donkers, M., Dubbert, J., Duchovni, E., Duckeck, G., Duerdoth, I.P., Estabrooks, P.G., Etzion, E., Fabbri, F., Fanfani, A., Fanti, M., Faust, A.A., Feld, L., Ferrari, P., Fiedler, F., Fierro, M., Fleck, I., Frey, A., Furtjes, A., Futyan, D.I., Gagnon, P., Gary, J.W., Gaycken, G., Geich-Gimbel, C., Giacomelli, G., Giacomelli, P., Gibson, W.R., Gingrich, D.M., Glenzinski, D., Goldberg, J., Gorn, W., Grandi, C., Graham, K., Gross, E., Grunhaus, J., Gruwe, M., Hajdu, C., Hanson, G.G., Hansroul, M., Hapke, M., Harder, K., Harel, A., Hargrove, C.K., Harin-Dirac, M., Hauschild, M., Hawkes, C.M., Hawkings, R., Hemingway, R.J., Herten, G., Heuer, R.D., Hildreth, M.D., Hill, J.C., Hobson, P.R., Hocker, James Andrew, Hoffman, Kara Dion, Homer, R.J., Honma, A.K., Horvath, D., Hossain, K.R., Howard, R., Huntemeyer, P., Igo-Kemenes, P., Imrie, D.C., Ishii, K., Jacob, F.R., Jawahery, A., Jeremie, H., Jimack, M., Jones, C.R., Jovanovic, P., Junk, T.R., Kanaya, N., Kanzaki, J., Karlen, D., Kartvelishvili, V., Kawagoe, K., Kawamoto, T., Kayal, P.I., Keeler, R.K., Kellogg, R.G., Kennedy, B.W., Kim, D.H., Klier, A., Kobayashi, T., Kobel, M., Kokott, T.P., Kolrep, M., Komamiya, S., Kowalewski, Robert V., Kress, T., Krieger, P., von Krogh, J., Kuhl, T., Kyberd, P., Lafferty, G.D., Landsman, H., Lanske, D., Lauber, J., Lawson, I., Layter, J.G., Lellouch, D., Letts, J., Levinson, L., Liebisch, R., Lillich, J., List, B., Littlewood, C., Lloyd, A.W., Lloyd, S.L., Loebinger, F.K., Long, G.D., Losty, M.J., Lu, J., Ludwig, J., Lui, D., Macchiolo, A., Macpherson, A., Mader, W., Mannelli, M., Marcellini, S., Marchant, T.E., Martin, A.J., Martin, J.P., Martinez, G., Mashimo, T., Mattig, Peter, McDonald, W.John, McKenna, J., Mckigney, E.A., McMahon, T.J., McPherson, R.A., Meijers, F., Mendez-Lorenzo, P., Merritt, F.S., Mes, H., Meyer, I., Michelini, A., Mihara, S., Mikenberg, G., Miller, D.J., Mohr, W., Montanari, A., Mori, T., Nagai, K., Nakamura, I., Neal, H.A., Nisius, R., O'Neale, S.W., Oakham, F.G., Odorici, F., Ogren, H.O., Okpara, A., Oreglia, M.J., Orito, S., Pasztor, G., Pater, J.R., Patrick, G.N., Patt, J., Perez-Ochoa, R., Petzold, S., Pfeifenschneider, P., Pilcher, J.E., Pinfold, J., Plane, David E., Poffenberger, P., Poli, B., Polok, J., Przybycien, M., Quadt, A., Rembser, C., Rick, H., Robertson, S., Robins, S.A., Rodning, N., Roney, J.M., Rosati, S., Roscoe, K., Rossi, A.M., Rozen, Y., Runge, K., Runolfsson, O., Rust, D.R., Sachs, K., Saeki, T., Sahr, O., Sang, W.M., Sarkisian, E.K.G., Sbarra, C., Schaile, A.D., Schaile, O., Scharff-Hansen, P., Schieck, J., Schmitt, S., Schoning, A., Schroder, Matthias, Schumacher, M., Schwick, C., Scott, W.G., Seuster, R., Shears, T.G., Shen, B.C., Shepherd-Themistocleous, C.H., Sherwood, P., Siroli, G.P., Skuja, A., Smith, A.M., Snow, G.A., Sobie, R., Soldner-Rembold, S., Spagnolo, S., Sproston, M., Stahl, A., Stephens, K., Stoll, K., Strom, David M., Strohmer, R., Surrow, B., Talbot, S.D., Taras, P., Tarem, S., Teuscher, R., Thiergen, M., Thomas, J., Thomson, M.A., Torrence, E., Towers, S., Trefzger, T., Trigger, I., Trocsanyi, Z., Tsur, E., Turner-Watson, M.F., Ueda, I., Van Kooten, Rick J., Vannerem, P., Verzocchi, M., Voss, H., Wackerle, F., Wagner, A., Waller, D., Ward, C.P., Ward, D.R., Watkins, P.M., Watson, A.T., Watson, N.K., Wells, P.S., Wermes, N., Wetterling, D., White, J.S., Wilson, G.W., Wilson, J.A., Wyatt, T.R., Yamashita, S., Zacek, V., and Zer-Zion, D.

Subjects
High Energy Physics::Phenomenology, High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment
Abstract

A search for charginos and neutralinos, predicted by supersymmetric theories, is performed using a data sample of 182.1 pb-1 taken at a centre-of-mass energy of 189 GeV with the OPAL detector at LEP. No evidence for chargino or neutralino production is found. Upper limits on chargino and neutralino pair production cross-sections are obtained as a function of the chargino mass, the lightest neutralino mass and the second lightest neutralino mass. Within the Constrained Minimal Supersymmetric Standard Model framework, and for a chargino - neutralino mass difference of more than 5 GeV, the 95% confidence level lower limits on the chargino mass are 93.6 GeV for tan{beta} = 1.5 and 94.1 GeV for tan{beta} = 35. These limits are obtained assuming a universal scalar mass m_0 > 500 GeV. The corresponding limits for all m_0 are 78.0 and 71.7 GeV. The 95% confidence level lower limits on the lightest neutralino mass, valid for any value of tan{beta} are 32.8 GeV for m_0 > 500 GeV and 31.6 GeV for all m_0. A search for charginos and neutralinos, predicted by supersymmetric theories, is performed using a data sample of 182.1 pb-1 taken at a centre-of-mass energy of 189 GeV with the OPAL detector at LEP. No evidence for chargino or neutralino production is found. Upper limits on chargino and neutralino pair production cross-sections are obtained as a function of the chargino mass, the lightest neutralino mass and the second lightest neutralino mass. Within the Constrained Minimal Supersymmetric Standard Model framework, and for a chargino - neutralino mass difference of more than 5 GeV, the 95% confidence level lower limits on the chargino mass are 93.6 GeV for tan{beta} = 1.5 and 94.1 GeV for tan{beta} = 35. These limits are obtained assuming a universal scalar mass m_0 > 500 GeV. The corresponding limits for all m_0 are 78.0 and 71.7 GeV. The 95% confidence level lower limits on the lightest neutralino mass, valid for any value of tan{beta} are 32.8 GeV for m_0 > 500 GeV and 31.6 GeV for all m_0.

Published
1999

213. Search for Anomalous Production of Acoplanar Di-lepton Events in $e^{+}e^{-}$ Collisions at $\sqrt{s}$=183 and 189 GeV

Author

Abbiendi, G., Ackerstaff, K., Alexander, G., Allison, John, Anderson, K.J., Anderson, S., Arcelli, S., Asai, S., Ashby, S.F., Axen, D., Azuelos, G., Ball, A.H., Barberio, E., Barlow, Roger J., Batley, J.R., Baumann, S., Bechtluft, J., Behnke, T., Bell, Kenneth Watson, Bella, G., Bellerive, A., Bentvelsen, S., Bethke, S., Betts, S., Biebel, O., Biguzzi, A., Bloodworth, I.J., Bock, P., Bohme, J., Boeriu, O., Bonacorsi, D., Boutemeur, M., Braibant, S., Bright-Thomas, P., Brigliadori, L., Brown, Robert M., Burckhart, H.J., Capiluppi, P., Carnegie, R.K., Carter, A.A., Carter, J.R., Chang, C.Y., Charlton, David G., Chrisman, D., Ciocca, C., Clarke, P.E.L., Clay, E., Cohen, I., Conboy, J.E., Cooke, O.C., Couchman, J., Couyoumtzelis, C., Coxe, R.L., Cuffiani, M., Dado, S., Dallavalle, G.Marco, Dallison, S., Davis, R., De Jong, S., de Roeck, A., Dervan, P., Desch, K., Dienes, B., Dixit, M.S., Donkers, M., Dubbert, J., Duchovni, E., Duckeck, G., Duerdoth, I.P., Estabrooks, P.G., Etzion, E., Fabbri, F., Fanfani, A., Fanti, M., Faust, A.A., Feld, L., Ferrari, P., Fiedler, F., Fierro, M., Fleck, I., Frey, A., Furtjes, A., Futyan, D.I., Gagnon, P., Gary, J.W., Gaycken, G., Geich-Gimbel, C., Giacomelli, G., Giacomelli, P., Gibson, W.R., Gingrich, D.M., Glenzinski, D., Goldberg, J., Gorn, W., Grandi, C., Graham, K., Gross, E., Grunhaus, J., Gruwe, M., Hajdu, C., Hanson, G.G., Hansroul, M., Hapke, M., Harder, K., Harel, A., Hargrove, C.K., Harin-Dirac, M., Hauschild, M., Hawkes, C.M., Hawkings, R., Hemingway, R.J., Herten, G., Heuer, R.D., Hildreth, M.D., Hill, J.C., Hobson, P.R., Hocker, James Andrew, Hoffman, Kara Dion, Homer, R.J., Honma, A.K., Horvath, D., Hossain, K.R., Howard, R., Huntemeyer, P., Igo-Kemenes, P., Imrie, D.C., Ishii, K., Jacob, F.R., Jawahery, A., Jeremie, H., Jimack, M., Jones, C.R., Jovanovic, P., Junk, T.R., Kanaya, N., Kanzaki, J., Karlen, D., Kartvelishvili, V., Kawagoe, K., Kawamoto, T., Kayal, P.I., Keeler, R.K., Kellogg, R.G., Kennedy, B.W., Kim, D.H., Klier, A., Kobayashi, T., Kobel, M., Kokott, T.P., Kolrep, M., Komamiya, S., Kowalewski, Robert V., Kress, T., Krieger, P., von Krogh, J., Kuhl, T., Kyberd, P., Lafferty, G.D., Landsman, H., Lanske, D., Lauber, J., Lawson, I., Layter, J.G., Lellouch, D., Letts, J., Levinson, L., Liebisch, R., Lillich, J., List, B., Littlewood, C., Lloyd, A.W., Lloyd, S.L., Loebinger, F.K., Long, G.D., Losty, M.J., Lu, J., Ludwig, J., Lui, D., Macchiolo, A., Macpherson, A., Mader, W., Mannelli, M., Marcellini, S., Marchant, T.E., Martin, A.J., Martin, J.P., Martinez, G., Mashimo, T., Mattig, Peter, McDonald, W.John, McKenna, J., Mckigney, E.A., McMahon, T.J., McPherson, R.A., Meijers, F., Mendez-Lorenzo, P., Merritt, F.S., Mes, H., Meyer, I., Michelini, A., Mihara, S., Mikenberg, G., Miller, D.J., Mohr, W., Montanari, A., Mori, T., Nagai, K., Nakamura, I., Neal, H.A., Nisius, R., O'Neale, S.W., Oakham, F.G., Odorici, F., Ogren, H.O., Okpara, A., Oreglia, M.J., Orito, S., Pasztor, G., Pater, J.R., Patrick, G.N., Patt, J., Perez-Ochoa, R., Petzold, S., Pfeifenschneider, P., Pilcher, J.E., Pinfold, J., Plane, David E., Poffenberger, P., Poli, B., Polok, J., Przybycien, M., Quadt, A., Rembser, C., Rick, H., Robertson, S., Robins, S.A., Rodning, N., Roney, J.M., Rosati, S., Roscoe, K., Rossi, A.M., Rozen, Y., Runge, K., Runolfsson, O., Rust, D.R., Sachs, K., Saeki, T., Sahr, O., Sang, W.M., Sarkisian, E.K.G., Sbarra, C., Schaile, A.D., Schaile, O., Scharff-Hansen, P., Schieck, J., Schmitt, S., Schoning, A., Schroder, Matthias, Schumacher, M., Schwick, C., Scott, W.G., Seuster, R., Shears, T.G., Shen, B.C., Shepherd-Themistocleous, C.H., Sherwood, P., Siroli, G.P., Skuja, A., Smith, A.M., Snow, G.A., Sobie, R., Soldner-Rembold, S., Spagnolo, S., Sproston, M., Stahl, A., Stephens, K., Stoll, K., Strom, David M., Strohmer, R., Surrow, B., Talbot, S.D., Taras, P., Tarem, S., Teuscher, R., Thiergen, M., Thomas, J., Thomson, M.A., Torrence, E., Towers, S., Trefzger, T., Trigger, I., Trocsanyi, Z., Tsur, E., Turner-Watson, M.F., Ueda, I., Van Kooten, Rick J., Vannerem, P., Verzocchi, M., Voss, H., Wackerle, F., Wagner, A., Waller, D., Ward, C.P., Ward, D.R., Watkins, P.M., Watson, A.T., Watson, N.K., Wells, P.S., Wermes, N., Wetterling, D., White, J.S., Wilson, G.W., Wilson, J.A., Wyatt, T.R., Yamashita, S., Zacek, V., and Zer-Zion, D.

Subjects
High Energy Physics::Phenomenology, High Energy Physics::Experiment, Particle Physics - Experiment
Abstract

A selection of di-lepton events with significant missing transverse momentum has been performed using a total data sample of 237.4 pb-1 at e+e- centre-of-mass energies of 183 GeV and 189 GeV. The observed numbers of events - 78 at 183 GeV and 301 at 189 GeV - are consistent with the numbers expected from Standard Model processes, which arise predominantly from W+W- production with each W decaying leptonically. This topology is also an experimental signature for the pair production of new particles that decay to a charged lepton accompanied by one or more invisible particles. Discrimination techniques are described that optimise the sensitivity to particular new physics channels. No evidence for new phenomena is apparent and model independent limits are presented on the production cross-section times branching ratio squared for sleptons and for leptonically decaying charginos and charged Higgs. Assuming a 100 % branching ratio for the decay of a slepton to a lepton and the lightest neutralino, we exclude at 95 % CL: right-handed smuons with masses below 82.3 GeV for a smuon-neutralino mass difference > 3 Gev and right-handed staus with masses below 81.0 GeV for a stau-neutralino mass difference > 8 GeV. Right-handed selectrons are excluded at 95% CL for masses below 87.1 GeV for a selectron-neutralino mass diffeerence > 5GeV, within the framework of the Minimal Supersymmetric Standard Model assuming mu < -100 GeV and tan{beta} = 1.5. Charged Higgs bosons are excluded at 95% CL for masses below 82.8GeV, assuming a 100% branching ratio for their decay to tau+neutrino. A selection of di-lepton events with significant missing transverse momentum has been performed using a total data sample of 237.4 pb-1 at e+e- centre-of-mass energies of 183 GeV and 189 GeV. The observed numbers of events - 78 at 183 GeV and 301 at 189 GeV - are consistent with the numbers expected from Standard Model processes, which arise predominantly from W+W- production with each W decaying leptonically. This topology is also an experimental signature for the pair production of new particles that decay to a charged lepton accompanied by one or more invisible particles. Discrimination techniques are described that optimise the sensitivity to particular new physics channels. No evidence for new phenomena is apparent and model independent limits are presented on the production cross-section times branching ratio squared for sleptons and for leptonically decaying charginos and charged Higgs. Assuming a 100 % branching ratio for the decay of a slepton to a lepton and the lightest neutralino, we exclude at 95 % CL: right-handed smuons with masses below 82.3 GeV for a smuon-neutralino mass difference > 3 Gev and right-handed staus with masses below 81.0 GeV for a stau-neutralino mass difference > 8 GeV. Right-handed selectrons are excluded at 95% CL for masses below 87.1 GeV for a selectron-neutralino mass diffeerence > 5GeV, within the framework of the Minimal Supersymmetric Standard Model assuming mu < -100 GeV and tan{beta} = 1.5. Charged Higgs bosons are excluded at 95% CL for masses below 82.8GeV, assuming a 100% branching ratio for their decay to tau+neutrino.

Published
1999

214. Search for Neutral Higgs Bosons in $e^{+}e^{-}$ Collisions at $\sqrt{s} \sim$ 189 GeV

Author

Abbiendi, G., Ackerstaff, K., Alexander, G., Allison, John, Anderson, K.J., Anderson, S., Arcelli, S., Asai, S., Ashby, S.F., Axen, D., Azuelos, G., Ball, A.H., Barberio, E., Barlow, Roger J., Batley, J.R., Baumann, S., Bechtluft, J., Behnke, T., Bell, Kenneth Watson, Bella, G., Bellerive, A., Bentvelsen, S., Bethke, S., Betts, S., Biebel, O., Biguzzi, A., Bloodworth, I.J., Bock, P., Bohme, J., Boeriu, O., Bonacorsi, D., Boutemeur, M., Braibant, S., Bright-Thomas, P., Brigliadori, L., Brown, Robert M., Burckhart, H.J., Capiluppi, P., Carnegie, R.K., Carter, A.A., Carter, J.R., Chang, C.Y., Charlton, David G., Chrisman, D., Ciocca, C., Clarke, P.E.L., Clay, E., Cohen, I., Conboy, J.E., Cooke, O.C., Couchman, J., Couyoumtzelis, C., Coxe, R.L., Cuffiani, M., Dado, S., Dallavalle, G.Marco, Dallison, S., Davis, R., De Jong, S., de Roeck, A., Dervan, P., Desch, K., Dienes, B., Dixit, M.S., Donkers, M., Dubbert, J., Duchovni, E., Duckeck, G., Duerdoth, I.P., Estabrooks, P.G., Etzion, E., Fabbri, F., Fanfani, A., Fanti, M., Faust, A.A., Feld, L., Ferrari, P., Fiedler, F., Fierro, M., Fleck, I., Frey, A., Furtjes, A., Futyan, D.I., Gagnon, P., Gary, J.W., Gaycken, G., Geich-Gimbel, C., Giacomelli, G., Giacomelli, P., Gibson, W.R., Gingrich, D.M., Glenzinski, D., Goldberg, J., Gorn, W., Grandi, C., Graham, K., Gross, E., Grunhaus, J., Gruwe, M., Hajdu, C., Hanson, G.G., Hansroul, M., Hapke, M., Harder, K., Harel, A., Hargrove, C.K., Harin-Dirac, M., Hauschild, M., Hawkes, C.M., Hawkings, R., Hemingway, R.J., Herten, G., Heuer, R.D., Hildreth, M.D., Hill, J.C., Hobson, P.R., Hocker, James Andrew, Hoffman, Kara Dion, Homer, R.J., Honma, A.K., Horvath, D., Hossain, K.R., Howard, R., Huntemeyer, P., Igo-Kemenes, P., Imrie, D.C., Ishii, K., Jacob, F.R., Jawahery, A., Jeremie, H., Jimack, M., Jones, C.R., Jovanovic, P., Junk, T.R., Kanaya, N., Kanzaki, J., Karlen, D., Kartvelishvili, V., Kawagoe, K., Kawamoto, T., Kayal, P.I., Keeler, R.K., Kellogg, R.G., Kennedy, B.W., Kim, D.H., Klier, A., Kobayashi, T., Kobel, M., Kokott, T.P., Kolrep, M., Komamiya, S., Kowalewski, Robert V., Kress, T., Krieger, P., von Krogh, J., Kuhl, T., Kyberd, P., Lafferty, G.D., Landsman, H., Lanske, D., Lauber, J., Lawson, I., Layter, J.G., Lellouch, D., Letts, J., Levinson, L., Liebisch, R., Lillich, J., List, B., Littlewood, C., Lloyd, A.W., Lloyd, S.L., Loebinger, F.K., Long, G.D., Losty, M.J., Lu, J., Ludwig, J., Lui, D., Macchiolo, A., Macpherson, A., Mader, W., Mannelli, M., Marcellini, S., Marchant, T.E., Martin, A.J., Martin, J.P., Martinez, G., Mashimo, T., Mattig, Peter, McDonald, W.John, McKenna, J., Mckigney, E.A., McMahon, T.J., McPherson, R.A., Meijers, F., Mendez-Lorenzo, P., Merritt, F.S., Mes, H., Meyer, I., Michelini, A., Mihara, S., Mikenberg, G., Miller, D.J., Mohr, W., Montanari, A., Mori, T., Nagai, K., Nakamura, I., Neal, H.A., Nisius, R., O'Neale, S.W., Oakham, F.G., Odorici, F., Ogren, H.O., Okpara, A., Oreglia, M.J., Orito, S., Pasztor, G., Pater, J.R., Patrick, G.N., Patt, J., Perez-Ochoa, R., Petzold, S., Pfeifenschneider, P., Pilcher, J.E., Pinfold, J., Plane, David E., Poffenberger, P., Poli, B., Polok, J., Przybycien, M., Quadt, A., Rembser, C., Rick, H., Robertson, S., Robins, S.A., Rodning, N., Roney, J.M., Rosati, S., Roscoe, K., Rossi, A.M., Rozen, Y., Runge, K., Runolfsson, O., Rust, D.R., Sachs, K., Saeki, T., Sahr, O., Sang, W.M., Sarkisian, E.K.G., Sbarra, C., Schaile, A.D., Schaile, O., Scharff-Hansen, P., Schieck, J., Schmitt, S., Schoning, A., Schroder, Matthias, Schumacher, M., Schwick, C., Scott, W.G., Seuster, R., Shears, T.G., Shen, B.C., Shepherd-Themistocleous, C.H., Sherwood, P., Siroli, G.P., Skuja, A., Smith, A.M., Snow, G.A., Sobie, R., Soldner-Rembold, S., Spagnolo, S., Sproston, M., Stahl, A., Stephens, K., Stoll, K., Strom, David M., Strohmer, R., Surrow, B., Talbot, S.D., Taras, P., Tarem, S., Teuscher, R., Thiergen, M., Thomas, J., Thomson, M.A., Torrence, E., Towers, S., Trefzger, T., Trigger, I., Trocsanyi, Z., Tsur, E., Turner-Watson, M.F., Ueda, I., Van Kooten, Rick J., Vannerem, P., Verzocchi, M., Voss, H., Wackerle, F., Wagner, A., Waller, D., Ward, C.P., Ward, D.R., Watkins, P.M., Watson, A.T., Watson, N.K., Wells, P.S., Wermes, N., Wetterling, D., White, J.S., Wilson, G.W., Wilson, J.A., Wyatt, T.R., Yamashita, S., Zacek, V., and Zer-Zion, D.

Subjects
High Energy Physics::Phenomenology, High Energy Physics::Experiment, Particle Physics - Experiment
Abstract

A search for neutral Higgs bosons has been performed with the OPAL detector at LEP, using approximately 170 pb-1 of e+e- collision data collected at sqrt(s)~189GeV. Searches have been performed for the Standard Model (SM) process e+e- to H0Z0 and the MSSM processes e+e- to H0Z0, A0h0. The searches are sensitive to the b b-bar and tau antitau decay modes of the Higgs bosons, and also to the MSSM decay mode h0 to A0A0. OPAL search results at lower centre-of-mass energies have been incorporated in the limits we set, which are valid at the 95% confidence level. For the SM Higgs boson, we obtain a lower mass bound of 91.0 GeV. In the MSSM, our limits are mh>74.8GeV and mA>76.5GeV, assuming tan(beta)>1, that the mixing of the scalar top quarks is either zero or maximal, and that the soft SUSY-breaking masses are 1 TeV. For the case of zero scalar top mixing, we exclude values of tan(beta) between 0.72 and 2.19. A search for neutral Higgs bosons has been performed with the OPAL detector at LEP, using approximately 170 pb-1 of e+e- collision data collected at sqrt(s)~189GeV. Searches have been performed for the Standard Model (SM) process e+e- to H0Z0 and the MSSM processes e+e- to H0Z0, A0h0. The searches are sensitive to the b b-bar and tau antitau decay modes of the Higgs bosons, and also to the MSSM decay mode h0 to A0A0. OPAL search results at lower centre-of-mass energies have been incorporated in the limits we set, which are valid at the 95% confidence level. For the SM Higgs boson, we obtain a lower mass bound of 91.0 GeV. In the MSSM, our limits are mh>74.8GeV and mA>76.5GeV, assuming tan(beta)>1, that the mixing of the scalar top quarks is either zero or maximal, and that the soft SUSY-breaking masses are 1 TeV. For the case of zero scalar top mixing, we exclude values of tan(beta) between 0.72 and 2.19.

Published
1999

215. Search for pair-produced leptoquarks in $e^{+}e^{-}$ interactions at $\sqrt{s} \simeq$ 183 GeV

Author

Abbiendi, G., Ackerstaff, K., Alexander, G., Allison, John, Anderson, K.J., Anderson, S., Arcelli, S., Asai, S., Ashby, S.F., Axen, D., Azuelos, G., Ball, A.H., Barberio, E., Barlow, Roger J., Batley, J.R., Baumann, S., Bechtluft, J., Behnke, T., Bell, Kenneth Watson, Bella, G., Bellerive, A., Bentvelsen, S., Bethke, S., Betts, S., Biebel, O., Biguzzi, A., Bloodworth, I.J., Bock, P., Bohme, J., Boeriu, O., Bonacorsi, D., Boutemeur, M., Braibant, S., Bright-Thomas, P., Brigliadori, L., Brown, Robert M., Burckhart, H.J., Capiluppi, P., Carnegie, R.K., Carter, A.A., Carter, J.R., Chang, C.Y., Charlton, David G., Chrisman, D., Ciocca, C., Clarke, P.E.L., Clay, E., Cohen, I., Conboy, J.E., Cooke, O.C., Couchman, J., Couyoumtzelis, C., Coxe, R.L., Cuffiani, M., Dado, S., Dallavalle, G.Marco, Dallison, S., Davis, R., De Jong, S., de Roeck, A., Dervan, P., Desch, K., Dienes, B., Dixit, M.S., Donkers, M., Dubbert, J., Duchovni, E., Duckeck, G., Duerdoth, I.P., Estabrooks, P.G., Etzion, E., Fabbri, F., Fanfani, A., Fanti, M., Faust, A.A., Feld, L., Ferrari, P., Fiedler, F., Fierro, M., Fleck, I., Frey, A., Furtjes, A., Futyan, D.I., Gagnon, P., Gary, J.W., Gascon-Shotkin, S.M., Gaycken, G., Geich-Gimbel, C., Giacomelli, G., Giacomelli, P., Gibson, W.R., Gingrich, D.M., Glenzinski, D., Goldberg, J., Gorn, W., Grandi, C., Graham, K., Gross, E., Grunhaus, J., Gruwe, M., Hajdu, C., Hanson, G.G., Hansroul, M., Hapke, M., Harder, K., Harel, A., Hargrove, C.K., Harin-Dirac, M., Hauschild, M., Hawkes, C.M., Hawkings, R., Hemingway, R.J., Herten, G., Heuer, R.D., Hildreth, M.D., Hill, J.C., Hobson, P.R., Hocker, James Andrew, Hoffman, Kara Dion, Homer, R.J., Honma, A.K., Horvath, D., Hossain, K.R., Howard, R., Huntemeyer, P., Igo-Kemenes, P., Imrie, D.C., Ishii, K., Jacob, F.R., Jawahery, A., Jeremie, H., Jimack, M., Jones, C.R., Jovanovic, P., Junk, T.R., Kanaya, N., Kanzaki, J., Karlen, D., Kartvelishvili, V., Kawagoe, K., Kawamoto, T., Kayal, P.I., Keeler, R.K., Kellogg, R.G., Kennedy, B.W., Kim, D.H., Klier, A., Kobayashi, T., Kobel, M., Kokott, T.P., Kolrep, M., Komamiya, S., Kowalewski, Robert V., Kress, T., Krieger, P., von Krogh, J., Kuhl, T., Kyberd, P., Lafferty, G.D., Landsman, H., Lanske, D., Lauber, J., Lawson, I., Layter, J.G., Lellouch, D., Letts, J., Levinson, L., Liebisch, R., Lillich, J., List, B., Littlewood, C., Lloyd, A.W., Lloyd, S.L., Loebinger, F.K., Long, G.D., Losty, M.J., Lu, J., Ludwig, J., Lui, D., Macchiolo, A., Macpherson, A., Mader, W., Mannelli, M., Marcellini, S., Marchant, T.E., Martin, A.J., Martin, J.P., Martinez, G., Mashimo, T., Mattig, Peter, McDonald, W.John, McKenna, J., Mckigney, E.A., McMahon, T.J., McPherson, R.A., Meijers, F., Mendez-Lorenzo, P., Merritt, F.S., Mes, H., Meyer, I., Michelini, A., Mihara, S., Mikenberg, G., Miller, D.J., Mohr, W., Montanari, A., Mori, T., Nagai, K., Nakamura, I., Neal, H.A., Nisius, R., O'Neale, S.W., Oakham, F.G., Odorici, F., Ogren, H.O., Okpara, A., Oreglia, M.J., Orito, S., Pasztor, G., Pater, J.R., Patrick, G.N., Patt, J., Perez-Ochoa, R., Petzold, S., Pfeifenschneider, P., Pilcher, J.E., Pinfold, J., Plane, David E., Poffenberger, P., Poli, B., Polok, J., Przybycien, M., Quadt, A., Rembser, C., Rick, H., Robertson, S., Robins, S.A., Rodning, N., Roney, J.M., Rosati, S., Roscoe, K., Rossi, A.M., Rozen, Y., Runge, K., Runolfsson, O., Rust, D.R., Sachs, K., Saeki, T., Sahr, O., Sang, W.M., Sarkisian, E.K.G., Sbarra, C., Schaile, A.D., Schaile, O., Scharff-Hansen, P., Schieck, J., Schmitt, S., Schoning, A., Schroder, Matthias, Schumacher, M., Schwick, C., Scott, W.G., Seuster, R., Shears, T.G., Shen, B.C., Shepherd-Themistocleous, C.H., Sherwood, P., Siroli, G.P., Skuja, A., Smith, A.M., Snow, G.A., Sobie, R., Soldner-Rembold, S., Spagnolo, S., Sproston, M., Stahl, A., Stephens, K., Stoll, K., Strom, David M., Strohmer, R., Surrow, B., Talbot, S.D., Taras, P., Tarem, S., Teuscher, R., Thiergen, M., Thomas, J., Thomson, M.A., Torrence, E., Towers, S., Trefzger, T., Trigger, I., Trocsanyi, Z., Tsur, E., Turner-Watson, M.F., Ueda, I., Van Kooten, Rick J., Vannerem, P., Verzocchi, M., Voss, H., Wackerle, F., Wagner, A., Waller, D., Ward, C.P., Ward, D.R., Watkins, P.M., Watson, A.T., Watson, N.K., Wells, P.S., Wermes, N., Wetterling, D., White, J.S., Wilson, G.W., Wilson, J.A., Wyatt, T.R., Yamashita, S., Zacek, V., and Zer-Zion, D.

Subjects
High Energy Physics::Phenomenology, High Energy Physics::Experiment, Particle Physics - Experiment
Abstract

A search for pair-produced leptoquarks has been performed using a sample of e+e- collision events collected by the OPAL detector at LEP at e+e- centre-of-mass energies of about 183 GeV. The data sample corresponds to an integrated luminosity of 55.9 pb-1. The leptoquarks were assumed to be produced via couplings to the photon and the Z0 and then to decay within a single fermion generation. No evidence for contributions from leptoquark pair production processes was observed. Lower limits on scalar and vector leptoquark masses are obtained. The existing limits are improved in the region of large decay branching ratio to quark-neutrino. A search for pair-produced leptoquarks has been performed using a sample of e+e- collision events collected by the OPAL detector at LEP at e+e- centre-of-mass energies of about 183 GeV. The data sample corresponds to an integrated luminosity of 55.9 pb-1. The leptoquarks were assumed to be produced via couplings to the photon and the Z0 and then to decay within a single fermion generation. No evidence for contributions from leptoquark pair production processes was observed. Lower limits on scalar and vector leptoquark masses are obtained. The existing limits are improved in the region of large decay branching ratio to quark-neutrino.

Published
1999

216. Multi-photon production in $e^{+}e^{-}$ collisions at $\sqrt{s}$ = 189 GeV

Author

Abbiendi, G., Ackerstaff, K., Alexander, G., Allison, John, Anderson, K.J., Anderson, S., Arcelli, S., Asai, S., Ashby, S.F., Axen, D., Azuelos, G., Ball, A.H., Barberio, E., Barlow, Roger J., Batley, J.R., Baumann, S., Bechtluft, J., Behnke, T., Bell, Kenneth Watson, Bella, G., Bellerive, A., Bentvelsen, S., Bethke, S., Betts, S., Biebel, O., Biguzzi, A., Bloodworth, I.J., Bock, P., Bohme, J., Boeriu, O., Bonacorsi, D., Boutemeur, M., Braibant, S., Bright-Thomas, P., Brigliadori, L., Brown, Robert M., Burckhart, H.J., Capiluppi, P., Carnegie, R.K., Carter, A.A., Carter, J.R., Chang, C.Y., Charlton, David G., Chrisman, D., Ciocca, C., Clarke, P.E.L., Clay, E., Cohen, I., Conboy, J.E., Cooke, O.C., Couchman, J., Couyoumtzelis, C., Coxe, R.L., Cuffiani, M., Dado, S., Dallavalle, G.Marco, Dallison, S., Davis, R., De Jong, S., de Roeck, A., Dervan, P., Desch, K., Dienes, B., Dixit, M.S., Donkers, M., Dubbert, J., Duchovni, E., Duckeck, G., Duerdoth, I.P., Estabrooks, P.G., Etzion, E., Fabbri, F., Fanfani, A., Fanti, M., Faust, A.A., Feld, L., Ferrari, P., Fiedler, F., Fierro, M., Fleck, I., Frey, A., Furtjes, A., Futyan, D.I., Gagnon, P., Gary, J.W., Gaycken, G., Geich-Gimbel, C., Giacomelli, G., Giacomelli, P., Gibson, W.R., Gingrich, D.M., Glenzinski, D., Goldberg, J., Gorn, W., Grandi, C., Graham, K., Gross, E., Grunhaus, J., Gruwe, M., Hajdu, C., Hanson, G.G., Hansroul, M., Hapke, M., Harder, K., Harel, A., Hargrove, C.K., Harin-Dirac, M., Hauschild, M., Hawkes, C.M., Hawkings, R., Hemingway, R.J., Herten, G., Heuer, R.D., Hildreth, M.D., Hill, J.C., Hobson, P.R., Hocker, James Andrew, Hoffman, Kara Dion, Homer, R.J., Honma, A.K., Horvath, D., Hossain, K.R., Howard, R., Huntemeyer, P., Igo-Kemenes, P., Imrie, D.C., Ishii, K., Jacob, F.R., Jawahery, A., Jeremie, H., Jimack, M., Jones, C.R., Jovanovic, P., Junk, T.R., Kanaya, N., Kanzaki, J., Karlen, D., Kartvelishvili, V., Kawagoe, K., Kawamoto, T., Kayal, P.I., Keeler, R.K., Kellogg, R.G., Kennedy, B.W., Kim, D.H., Klier, A., Kobayashi, T., Kobel, M., Kokott, T.P., Kolrep, M., Komamiya, S., Kowalewski, Robert V., Kress, T., Krieger, P., von Krogh, J., Kuhl, T., Kyberd, P., Lafferty, G.D., Landsman, H., Lanske, D., Lauber, J., Lawson, I., Layter, J.G., Lellouch, D., Letts, J., Levinson, L., Liebisch, R., Lillich, J., List, B., Littlewood, C., Lloyd, A.W., Lloyd, S.L., Loebinger, F.K., Long, G.D., Losty, M.J., Lu, J., Ludwig, J., Lui, D., Macchiolo, A., Macpherson, A., Mader, W., Mannelli, M., Marcellini, S., Marchant, T.E., Martin, A.J., Martin, J.P., Martinez, G., Mashimo, T., Mattig, Peter, McDonald, W.John, McKenna, J., Mckigney, E.A., McMahon, T.J., McPherson, R.A., Meijers, F., Mendez-Lorenzo, P., Merritt, F.S., Mes, H., Meyer, I., Michelini, A., Mihara, S., Mikenberg, G., Miller, D.J., Mohr, W., Montanari, A., Mori, T., Nagai, K., Nakamura, I., Neal, H.A., Nisius, R., O'Neale, S.W., Oakham, F.G., Odorici, F., Ogren, H.O., Okpara, A., Oreglia, M.J., Orito, S., Pasztor, G., Pater, J.R., Patrick, G.N., Patt, J., Perez-Ochoa, R., Petzold, S., Pfeifenschneider, P., Pilcher, J.E., Pinfold, J., Plane, David E., Poffenberger, P., Poli, B., Polok, J., Przybycien, M., Quadt, A., Rembser, C., Rick, H., Robertson, S., Robins, S.A., Rodning, N., Roney, J.M., Rosati, S., Roscoe, K., Rossi, A.M., Rozen, Y., Runge, K., Runolfsson, O., Rust, D.R., Sachs, K., Saeki, T., Sahr, O., Sang, W.M., Sarkisian, E.K.G., Sbarra, C., Schaile, A.D., Schaile, O., Scharff-Hansen, P., Schieck, J., Schmitt, S., Schoning, A., Schroder, Matthias, Schumacher, M., Schwick, C., Scott, W.G., Seuster, R., Shears, T.G., Shen, B.C., Shepherd-Themistocleous, C.H., Sherwood, P., Siroli, G.P., Skuja, A., Smith, A.M., Snow, G.A., Sobie, R., Soldner-Rembold, S., Spagnolo, S., Sproston, M., Stahl, A., Stephens, K., Stoll, K., Strom, David M., Strohmer, R., Surrow, B., Talbot, S.D., Taras, P., Tarem, S., Teuscher, R., Thiergen, M., Thomas, J., Thomson, M.A., Torrence, E., Towers, S., Trefzger, T., Trigger, I., Trocsanyi, Z., Tsur, E., Turner-Watson, M.F., Ueda, I., Van Kooten, Rick J., Vannerem, P., Verzocchi, M., Voss, H., Wackerle, F., Wagner, A., Waller, D., Ward, C.P., Ward, D.R., Watkins, P.M., Watson, A.T., Watson, N.K., Wells, P.S., Wermes, N., Wetterling, D., White, J.S., Wilson, G.W., Wilson, J.A., Wyatt, T.R., Yamashita, S., Zacek, V., and Zer-Zion, D.

Subjects
High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment
Abstract

The process e+e- to 2 (or 3) gammas is studied using data recorded with the OPAL detector at LEP. The data sample taken at a centre-of-mass energy of 189 GeV corresponds to a total integrated luminosity of 178 pb-1. The measured cross-section agrees well with the expectation from QED. A fit to the angular distribution is used to obtain improved limits at 95% CL on the QED cut-off parameters: Lambda+ > 304 GeV and Lambda- > 295 GeV as well as a mass limit for an excited electron, Me* > 306 GeV assuming equal e*egamma and eegamma couplings. Graviton exchange in the context of theories with higher dimensions is excluded for scales G+ < 660 GeV and G- < 634 GeV. No evidence for resonance production is found in the invariant mass spectrum of photon pairs. Limits are obtained for the cross-section times branching ratio for a resonance decaying into two photons and produced in association with another photon. The process e+e- to 2 (or 3) gammas is studied using data recorded with the OPAL detector at LEP. The data sample taken at a centre-of-mass energy of 189 GeV corresponds to a total integrated luminosity of 178 pb-1. The measured cross-section agrees well with the expectation from QED. A fit to the angular distribution is used to obtain improved limits at 95% CL on the QED cut-off parameters: Lambda+ > 304 GeV and Lambda- > 295 GeV as well as a mass limit for an excited electron, Me* > 306 GeV assuming equal e*egamma and eegamma couplings. Graviton exchange in the context of theories with higher dimensions is excluded for scales G+ < 660 GeV and G- < 634 GeV. No evidence for resonance production is found in the invariant mass spectrum of photon pairs. Limits are obtained for the cross-section times branching ratio for a resonance decaying into two photons and produced in association with another photon. The process e+e- to 2 (or 3) gammas is studied using data recorded with the OPAL detector at LEP. The data sample taken at a centre-of-mass energy of 189 GeV corresponds to a total integrated luminosity of 178 pb-1. The measured cross-section agrees well with the expectation from QED. A fit to the angular distribution is used to obtain improved limits at 95% CL on the QED cut-off parameters: Lambda+ > 304 GeV and Lambda- > 295 GeV as well as a mass limit for an excited electron, Me* > 306 GeV assuming equal e*egamma and eegamma couplings. Graviton exchange in the context of theories with higher dimensions is excluded for scales G+ < 660 GeV and G- < 634 GeV. No evidence for resonance production is found in the invariant mass spectrum of photon pairs. Limits are obtained for the cross-section times branching ratio for a resonance decaying into two photons and produced in association with another photon. The process e+e- to 2 (or 3) gammas is studied using data recorded with the OPAL detector at LEP. The data sample taken at a centre-of-mass energy of 189 GeV corresponds to a total integrated luminosity of 178 pb-1. The measured cross-section agrees well with the expectation from QED. A fit to the angular distribution is used to obtain improved limits at 95% CL on the QED cut-off parameters: Lambda+ > 304 GeV and Lambda- > 295 GeV as well as a mass limit for an excited electron, Me* > 306 GeV assuming equal e*egamma and eegamma couplings. Graviton exchange in the context of theories with higher dimensions is excluded for scales G+ < 660 GeV and G- < 634 GeV. No evidence for resonance production is found in the invariant mass spectrum of photon pairs. Limits are obtained for the cross-section times branching ratio for a resonance decaying into two photons and produced in association with another photon. The process e + e − → γγ ( γ ) is studied using data recorded with the OPAL detector at LEP. The data sample taken at a centre-of-mass energy of 189 GeV corresponds to a total integrated luminosity of 178 pb −1 . The measured cross-section agrees well with the expectation from QED. A fit to the angular distribution is used to obtain improved limits at 95% CL on the QED cut-off parameters: Λ + > 304 GeV and Λ − > 295 GeV as well as a mass limit for an excited electron, M e ∗ > 306 GeV assuming equal e ∗ eγ and eeγ couplings. Graviton exchange in the context of theories with higher dimensions is excluded for scales G + < 660 GeV and G − < 634 GeV. No evidence for resonance production is found in the invariant mass spectrum of photon pairs. Limits are obtained for the cross-section times branching ratio for a resonance decaying into two photons and produced in association with another photon.

Published
1999

217. Precision Luminosity for Z0 Lineshape Measurements with a Silicon-Tungsten Calorimeter

Author

Abbiendi, G, Ackerstaff, K, Alexander, G, Allison, J, Anderson, KJ, Anderson, S, Arcelli, S, Asai, S, Ashby, SF, Axen, D, Azuelos, G, Graham, K, Gross, E, Grunhaus, J, Gruwe, M, Hajdu, C, Hanson, GG, Hansroul, M, Hapke, M, Harder, K, Harel, A, Ball, AH, Hargrove, CK, Harin-Dirac, M, Hart, P, Hauschild, M, Hawkes, CM, Hawkings, R, Hemingway, RJ, Herten, G, Heuer, RD, Hildreth, MD, Barberio, E, Hill, JC, Hillier, S, Hobson, PR, Hocker, A, Hoffman, K, Homer, RJ, Honma, AK, Horvath, D, Hossain, KR, Howard, R, Barlow, RJ, Huntemeyer, P, Igo-Kemenes, P, Imrie, DC, Ishii, K, Jacob, FR, Jawahery, A, Jeremie, H, Jimack, M, Jones, CR, Jovanovic, P, Batley, JR, Junk, TR, Kanaya, N, Kanzaki, J, Karlen, D, Kartvelishvili, V, Kawagoe, K, Kawamoto, T, Kayal, PI, Keeler, RK, Kellogg, RG, Baumann, S, Kennedy, BW, Kim, DH, Kirk, J, Klier, A, Kobayashi, T, Kobel, M, Kokott, TP, Kolrep, M, Komamiya, S, Kowalewski, RV, Bechtluft, J, Kress, T, Krieger, P, von Krogh, J, Kuhl, T, Kyberd, P, Lai, WP, Lafferty, GD, Lahmann, R, Landsman, H, Lanske, D, Behnke, T, Lauber, J, Lawson, I, Layter, JG, Lee, AM, Lellouch, D, Letts, J, Levinson, L, Liebisch, R, Lillich, J, List, B, Bell, KW, Littlewood, C, Lloyd, AW, Lloyd, SL, Loebinger, FK, Long, GD, Losty, MJ, Lu, J, Ludwig, J, Liu, D, Macchiolo, A, Bella, G, Macpherson, A, Mader, W, Mannelli, M, Marcellini, S, Marchant, TE, Martin, AJ, Martin, JP, Martinez, G, Mashimo, T, Mattig, P, Bellerive, A, McDonald, WJ, McKenna, J, Mckigney, EA, McMahon, TJ, McPherson, RA, Meijers, F, Mendez-Lorenzo, P, Menke, S, Merritt, FS, Mes, H, Bentvelsen, S, Meyer, I, Michelini, A, Mihara, S, Mikenberg, G, Miller, DJ, Mohr, W, Montanari, A, Mori, T, Muller, U, Nagai, K, Bethke, S, Nakamura, I, Neal, HA, Nisius, R, O'Neale, SW, Oakham, FG, Odorici, F, Ogren, HO, Okpara, A, Oreglia, MJ, Orito, S, Betts, S, Palmonari, F, Pasztor, G, Pater, JR, Patrick, GN, Patt, J, Perez-Ochoa, R, Petzold, S, Pfeifenschneider, P, Pilcher, JE, Pinfold, J, Biebel, O, Plane, DE, Poffenberger, P, Poli, B, Polok, J, Przybycien, M, Quadt, A, Raith, B, Rembser, C, Rick, H, Robertson, S, Biguzzi, A, Robins, SA, Rodning, N, Roney, JM, Rosati, S, Roscoe, K, Rossi, AM, Rozen, Y, Runge, K, Runolfsson, O, Rust, DR, Bloodworth, IJ, Sachs, K, Saeki, T, Sahr, O, Sang, WM, Sarkisyan, EKG, Sbarra, C, Schaile, AD, Schaile, O, Scharff-Hansen, P, Schieck, J, Bock, P, Schmitt, B, Schmitt, S, Schoning, A, Schroder, M, Schumacher, M, Schwick, C, Scott, WG, Seuster, R, Shears, TG, Shen, BC, Bohme, J, Shepherd-Themistocleous, CH, Sherwood, P, Siroli, GP, Skuja, A, Smith, AM, Snow, GA, Sobie, R, Soldner-Rembold, S, Spagnolo, S, Springer, W, Boeriu, O, Sproston, M, Stahl, A, Stephens, K, Stoll, K, Strom, D, Strohmer, R, Surrow, B, Talbot, SD, Taras, P, Tarem, S, Bonacorsi, D, Tecchio, M, Teuscher, R, Thiergen, M, Thomas, J, Thomson, MA, Torrence, E, Towers, S, Trefzger, T, Trigger, I, Trocsanyi, Z, Boutemeur, M, Tsur, E, Turner-Watson, MF, Ueda, I, Van Kooten, R, Vannerem, P, Verzocchi, M, Voss, H, Wackerle, F, Wagner, A, Wagner, D, Braibant, S, Waller, D, Ward, CP, Ward, DR, Watkins, PM, Watson, AT, Watson, NK, Wells, PS, Wermes, N, Wetterling, D, White, JS, Bright-Thomas, P, Wilson, GW, Wilson, JA, Wyatt, TR, Yamashita, S, Zacek, V, Zer-Zion, D, OPAL Collaboration, Brigliadori, L, Brown, RM, Burckhart, HJ, Capiluppi, P, Carnegie, RK, Carter, AA, Carter, JR, Chang, CY, Charlton, DG, Chrisman, D, Ciocca, C, Clarke, PEL, Clay, E, Cohen, I, Conboy, JE, Cooke, OC, Couchman, J, Couyoumtzelis, C, Coxe, RL, Cuffiani, M, Dado, S, Dallavalle, GM, Dallison, S, Darling, C, Davis, R, De Jong, S, de Roeck, A, Dervan, P, Desch, K, Dienes, B, Dixit, MS, Donkers, M, Dubbert, J, Duchovni, E, Duckeck, G, Duerdoth, IP, Estabrooks, PG, Etzion, E, Evans, H, Fabbri, F, Fanfani, A, Fanti, M, Faust, AA, Feld, L, Ferrari, P, Fiedler, F, Fierro, M, Fleck, I, Foucher, M, Frey, A, Furtjes, A, Futyan, DI, Gagnon, P, Gary, JW, Gascon-Shotkin, S, Gaycken, G, Geich-Gimbel, C, Giacomelli, G, Giacomelli, P, Giacomelli, R, Gibson, WR, Gingrich, DM, Glenzinski, D, Goldberg, J, Gorn, W, Grandi, C, G., Abbiendi, K., Ackerstaff, G., Alexander, J., Allison, K. J., Anderson, S., Anderson, S., Arcelli, S., Asai, S. F., Ashby, D., Axen, G., Azuelo, A. H., Ball, E., Barberio, R. J., Barlow, J. R., Batley, S., Baumann, J., Bechtluft, T., Behnke, K. W., Bell, G., Bella, A., Bellerive, S., Bentvelsen, S., Bethke, S., Bett, O., Biebel, A., Biguzzi, I. J., Bloodworth, P., Bock, J., Bohme, O., Boeriu, D., Bonacorsi, M., Boutemeur, S., Braibant, P., Bright Thoma, L., Brigliadori, R. M., Brown, H. J., Burckhart, P., Capiluppi, R. K., Carnegie, A. A., Carter, J. R., Carter, C. Y., Chang, D. G., Charlton, D., Chrisman, C., Ciocca, P. E., L., E., Clay, I., Cohen, J. E., Conboy, O. C., Cooke, J., Couchman, C., Couyoumtzeli, R. L., Coxe, M., Cuffiani, S., Dado, G. M., Dallavalle, S., Dallison, C., Darling, R., Davi, S., De Jong, A., de Roeck, P., Dervan, K., Desch, B., Diene, M. S., Dixit, M., Donker, J., Dubbert, E., Duchovni, G., Duckeck, I. P., Duerdoth, P. G., Estabrook, E., Etzion, H., Evan, F., Fabbri, A., Fanfani, M., Fanti, A. A., Faust, L., Feld, P., Ferrari, F., Fiedler, M., Fierro, I., Fleck, M., Foucher, A., Frey, A., Furtje, D. I., Futyan, P., Gagnon, J. W., Gary, S., Gascon Shotkin, G., Gaycken, C., Geich Gimbel, G., Giacomelli, P., Giacomelli, R., Giacomelli, W. R., Gibson, D. M., Gingrich, D., Glenzinski, J., Goldberg, W., Gorn, C., Grandi, K., Graham, E., Gro, J., Grunhau, M., Gruwe, C., Hajdu, G. G., Hanson, M., Hansroul, M., Hapke, K., Harder, A., Harel, C. K., Hargrove, M., Harin Dirac, P., Hart, M., Hauschild, C. M., Hawke, R., Hawking, R. J., Hemingway, G., Herten, R. D., Heuer, M. D., Hildreth, J. C., Hill, S., Hillier, P. R., Hobson, A., Hocker, K., Hoffman, R. J., Homer, A. K., Honma, D., Horvath, K. R., Hossain, R., Howard, P., Huntemeyer, P., Igo Kemene, D. C., Imrie, K., Ishii, F. R., Jacob, A., Jawahery, H., Jeremie, M., Jimack, C. R., Jone, P., Jovanovic, T. R., Junk, N., Kanaya, J., Kanzaki, D., Karlen, V., Kartvelishvili, K., Kawagoe, T., Kawamoto, P. I., Kayal, R. K., Keeler, R. G., Kellogg, B. W., Kennedy, D. H., Kim, J., Kirk, A., Klier, T., Kobayashi, M., Kobel, T. P., Kokott, M., Kolrep, S., Komamiya, R. V., Kowalewski, T., Kre, P., Krieger, J., von Krogh, T., Kuhl, P., Kyberd, W. P., Lai, G. D., Lafferty, R., Lahmann, H., Landsman, D., Lanske, J., Lauber, I., Lawson, J. G., Layter, A. M., Lee, D., Lellouch, J., Lett, L., Levinson, R., Liebisch, J., Lillich, B., List, C., Littlewood, A. W., Lloyd, S. L., Lloyd, F. K., Loebinger, G. D., Long, M. J., Losty, J., Lu, J., Ludwig, D., Liu, A., Macchiolo, A., Macpherson, W., Mader, M., Mannelli, S., Marcellini, T. E., Marchant, A. J., Martin, J. P., Martin, G., Martinez, T., Mashimo, P., Mattig, W. J., Mcdonald, J., Mckenna, E. A., Mckigney, T. J., Mcmahon, R. A., Mcpherson, F., Meijer, P., Mendez Lorenzo, S., Menke, F. S., Merritt, H., Me, I., Meyer, A., Michelini, S., Mihara, G., Mikenberg, D. J., Miller, W., Mohr, A., Montanari, T., Mori, U., Muller, K., Nagai, I., Nakamura, H. A., Neal, R., Nisiu, S. W., O'Neale, F. G., Oakham, F., Odorici, H. O., Ogren, A., Okpara, M. J., Oreglia, S., Orito, F., Palmonari, G., Pasztor, J. R., Pater, G. N., Patrick, J., Patt, R., Perez Ochoa, S., Petzold, P., Pfeifenschneider, J. E., Pilcher, J., Pinfold, D. E., Plane, P., Poffenberger, B., Poli, J., Polok, M., Przybycien, A., Quadt, B., Raith, C., Rembser, H., Rick, S., Robertson, S. A., Robin, N., Rodning, J. M., Roney, S., Rosati, K., Roscoe, A. M., Rossi, Y., Rozen, K., Runge, O., Runolfsson, D. R., Rust, K., Sach, T., Saeki, O., Sahr, W. M., Sang, E. K., G., C., Sbarra, A. D., Schaile, O., Schaile, P., Scharff Hansen, J., Schieck, B., Schmitt, S., Schmitt, A., Schoning, M., Schroder, M., Schumacher, C., Schwick, W. G., Scott, R., Seuster, T. G., Shear, B. C., Shen, C. H., Shepherd Themistocleou, P., Sherwood, G. P., Siroli, A., Skuja, A. M., Smith, G. A., Snow, R., Sobie, S., Soldner Rembold, Spagnolo, Stefania Antonia, W., Springer, M., Sproston, A., Stahl, K., Stephen, K., Stoll, D., Strom, R., Strohmer, B., Surrow, S. D., Talbot, P., Tara, S., Tarem, M., Tecchio, R., Teuscher, M., Thiergen, J., Thoma, M. A., Thomson, E., Torrence, S., Tower, T., Trefzger, I., Trigger, Z., Trocsanyi, E., Tsur, M. F., Turner Watson, I., Ueda, R., Van Kooten, P., Vannerem, M., Verzocchi, H., Vo, F., Wackerle, A., Wagner, D., Wagner, D., Waller, C. P., Ward, D. R., Ward, P. M., Watkin, A. T., Watson, N. K., Watson, P. S., Well, N., Werme, D., Wetterling, J. S., White, G. W., Wilson, J. A., Wilson, T. R., Wyatt, S., Yamashita, V., Zacek, and D., Zer Zion

Subjects
LOW-NOISE, Particle physics, E+E ANNIHILATION, Photon, Physics and Astronomy (miscellaneous), Physics::Instrumentation and Detectors, FOS: Physical sciences, Electron, INCLUSIVE MUON PRODUCTION, 01 natural sciences, OPAL DETECTOR, Radiation length, High Energy Physics - Experiment, Nuclear physics, BHABHA SCATTERING, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, 010306 general physics, Engineering (miscellaneous), Bhabha scattering, Physics, Luminosity (scattering theory), Interaction point, ELECTROWEAK PARAMETERS, 010308 nuclear & particles physics, CMOS SIGNAL PROCESSOR, MICROVERTEX DETECTOR, SMALL-ANGLE, Calorimeter, TOTAL CROSS-SECTION, High Energy Physics::Experiment, Event (particle physics), Particle Physics - Experiment
Abstract

The measurement of small-angle Bhabha scattering is used to determine the luminosity at the OPAL interaction point for the LEP I data recorded between 1993 and 1995. The measurement is based on the OPAL Silicon-Tungsten Luminometer which is composed of two calorimeters encircling the LEP beam pipe, on opposite sides of the interaction point. The luminometer detects electrons from small-angle Bhabha scattering at angles between 25 and 58mrad. At LEP center-of-mass energies around the Z0, about half of all Bhabha electrons entering the detector fall within a 79nb fiducial acceptance region. The electromagnetic showers generated in the stack of 1 radiation length tungsten absorber plates are sampled by 608 silicon detectors with 38,912 radial pads of 2.5mm width.The fine segmentation of the detector, combined with the precise knowledge of its physical dimensions, allows the trajectories of incoming 45GeV electrons or photons to be determined with a total systematic error of less than 7microns. We have quantified all significant sources of systematic experimental error in the luminosity determination by direct physical measurement. All measured properites of the luminosity event sample are found to be in agreement with current theoretical expectations. The total systematic measurement uncertainty is 3.4x10^-4, significantly below the theoretical error of 5.4x10^-4 currently assigned to the QED calculation of the Bhabha acceptance, and contributes negligibly to the total uncertainty in the OPAL measurement of Gamma{invisible}/Gamma{l+l-}, a quantity of basic physical interest which depends crucially on the luminosity measurement., Comment: 87 pages, 36 figures, submitted to Eur.Phys. J. C. Updated references

Published
1999
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218. Increase in African dust flux at the onset of commercial agriculture in the Sahel region

Author

Mulitza, S., Heslop, D., Pittauerová, D., Fischer, Hubertus, Meyer, I., Stuut, J.-B., Zabel, M., Mollenhauer, Gesine, Collins, J. A., Kuhnert, H., Schulz, Maximilian, Mulitza, S., Heslop, D., Pittauerová, D., Fischer, Hubertus, Meyer, I., Stuut, J.-B., Zabel, M., Mollenhauer, Gesine, Collins, J. A., Kuhnert, H., and Schulz, Maximilian

Published
2010

221. The genome of the simian and human malaria parasite Plasmodium knowlesi

Author

Pain, A, Böhme, U, Berry, A E, Mungall, K, Finn, R D, Jackson, A P, Mourier, T, Mistry, J, Pasini, E M, Aslett, M A, Balasubrammaniam, S, Borgwardt, K, Brooks, K, Carret, C, Carver, T J, Cherevach, I, Chillingworth, T, Clark, T G, Galinski, M R, Hall, N, Harper, D, Harris, D, Hauser, H, Ivens, A, Janssen, C S, Keane, T, Larke, N, Lapp, S, Marti, M, Moule, S, Meyer, I M, Ormond, D, Peters, N, Sanders, M, Sanders, S, Sargeant, T J, Simmonds, M, Smith, F, Squares, R, Thurston, S, Tivey, A R, Walker, D, White, B, Zuiderwijk, E, Churcher, C, Quail, M A, Cowman, A F, Turner, C M R, Rajandream, M A, Kocken, C H M, Thomas, A W, Newbold, C I, Barrell, B G, Berriman, M, Pain, A, Böhme, U, Berry, A E, Mungall, K, Finn, R D, Jackson, A P, Mourier, T, Mistry, J, Pasini, E M, Aslett, M A, Balasubrammaniam, S, Borgwardt, K, Brooks, K, Carret, C, Carver, T J, Cherevach, I, Chillingworth, T, Clark, T G, Galinski, M R, Hall, N, Harper, D, Harris, D, Hauser, H, Ivens, A, Janssen, C S, Keane, T, Larke, N, Lapp, S, Marti, M, Moule, S, Meyer, I M, Ormond, D, Peters, N, Sanders, M, Sanders, S, Sargeant, T J, Simmonds, M, Smith, F, Squares, R, Thurston, S, Tivey, A R, Walker, D, White, B, Zuiderwijk, E, Churcher, C, Quail, M A, Cowman, A F, Turner, C M R, Rajandream, M A, Kocken, C H M, Thomas, A W, Newbold, C I, Barrell, B G, and Berriman, M

Abstract

Udgivelsesdato: 2008-Oct-9, Plasmodium knowlesi is an intracellular malaria parasite whose natural vertebrate host is Macaca fascicularis (the 'kra' monkey); however, it is now increasingly recognized as a significant cause of human malaria, particularly in southeast Asia. Plasmodium knowlesi was the first malaria parasite species in which antigenic variation was demonstrated, and it has a close phylogenetic relationship to Plasmodium vivax, the second most important species of human malaria parasite (reviewed in ref. 4). Despite their relatedness, there are important phenotypic differences between them, such as host blood cell preference, absence of a dormant liver stage or 'hypnozoite' in P. knowlesi, and length of the asexual cycle (reviewed in ref. 4). Here we present an analysis of the P. knowlesi (H strain, Pk1(A+) clone) nuclear genome sequence. This is the first monkey malaria parasite genome to be described, and it provides an opportunity for comparison with the recently completed P. vivax genome and other sequenced Plasmodium genomes. In contrast to other Plasmodium genomes, putative variant antigen families are dispersed throughout the genome and are associated with intrachromosomal telomere repeats. One of these families, the KIRs, contains sequences that collectively match over one-half of the host CD99 extracellular domain, which may represent an unusual form of molecular mimicry.

Published
2008

225. EXPLORING THE USE OF COMPUTER-MEDIATED VIDEO COMMUNICATION IN ENGINEERING PROJECTS IN SOUTH AFRICA.

Author

Meyer, I. P., Bond-Barnard, T. J., Steyn, H., and Jordaan, J.

Subjects
*SIGNALING (Psychology), *COMMUNICATION strategies, *COMMUNICATION methodology, *TIME pressure, *PSYCHOLOGICAL stress
Abstract

Globally-expanding organisations that are trying to capitalise on distributed skills are increasingly using virtual project teams to shorten product development time and increase quality. These virtual teams, which are distributed across countries, cultures, and time zones, are required to use faster and better ways of interacting. Past research has shown that virtual teams that use computer-mediated communication (CMC) instead of face-to-face communication are less cohesive because they struggle with mistrust, controlling behaviour, and communication breakdowns. This study aims to determine whether project practitioners in South Africa perceive virtual teams that use videoconferencing as suffering from the same CMC disadvantages described in past research in other environments; and if they do, what the possible causes could be. This paper reports on a survey of 106 project practitioners in South Africa. The results show that these project practitioners prefer faceto- face communication over CMC, and perceive virtual teams using videoconferencing to be less cohesive and to suffer from mistrust and communication breakdowns, but not from increased conflict and power struggles. The perceived shortcomings of videoconferencing might result from virtual teams that use this medium having less time to build interpersonal relationships. [ABSTRACT FROM AUTHOR]

Published
2016
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226. Hepatitis C virus seroprevalence in adults in Africa: a systematic review and meta-analysis.

Author

Riou, J., Aït Ahmed, M., Blake, A., Vozlinsky, S., Brichler, S., Eholié, S., Boëlle, P.‐Y., Fontanet, A., Thursz, Mark, Chevaliez, Stéphane, Girard, Pierre‐Marie, Akinbami, AA, Andrieux‐Meyer, I, Berkane, S, Candotti, D, Cohn, J, Diarra, AA, Dirisu, J, Siawaya, JF, and Dore, G

Subjects
CHRONIC hepatitis C, SEROPREVALENCE, HEALTH of adults, EPIDEMIOLOGY, SYSTEMATIC reviews, META-analysis, PATIENTS
Abstract

With the introduction of more efficient treatments for hepatitis C virus ( HCV), improved epidemiological information is required at the country level to allow evidence-based policymaking for elaboration of national strategies and HCV resources planning. We present a systematic review with meta-analysis of HCV seroprevalence data in adults in African countries. We conducted a systematic review of all HCV seroprevalence estimates reported in African countries from 2000 to 2014 in MEDLINE, AJOL and grey literature. We assessed studies performed in the general population and among blood donors, pregnant women and HIV-positive patients. A meta-regression analysis was used to provide adjusted estimates of HCV seroprevalence in the general adult population in each country, accounting for the heterogeneity in sample age structure and population types in the included studies. We identified 775 national-level estimations, among which 184 were included. Estimates of HCV seroprevalence were produced for 38 countries, in addition to the results from nationwide representative surveys available in Egypt and Libya. Next to Egypt, which clearly stands out, the highest levels of seroprevalence were found in Middle Africa (e.g. Cameroon, Gabon and Angola) and some West African countries (e.g. Burkina Faso, Benin), and the largest absolute numbers of infected adults were found in Nigeria, Ethiopia and Democratic Republic of Congo. This study exposes the diversity of HCV epidemiology among African countries. Egypt and several countries of West and Middle Africa present a HCV burden that will require strong governmental commitment to promote efficient preventive and curative interventions. [ABSTRACT FROM AUTHOR]

Published
2016
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230. Scytalidiose disséminée chez un greffe rénal

Author

Fekkar, A., primary, Arzouk, N., additional, Barete, S., additional, Michon, A., additional, Lecso, G., additional, Meyer, I., additional, Palous, M., additional, Toper, C., additional, Barrou, B., additional, Frances, C., additional, and Datry, A., additional

Published
2012
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232. The 7–13 March 2006 major Saharan outbreak: Multiproxy characterization of mineral dust deposited on the West African margin

Author

Skonieczny, C., primary, Bory, A., additional, Bout-Roumazeilles, V., additional, Abouchami, W., additional, Galer, S. J. G., additional, Crosta, X., additional, Stuut, J.-B., additional, Meyer, I., additional, Chiapello, I., additional, Podvin, T., additional, Chatenet, B., additional, Diallo, A., additional, and Ndiaye, T., additional

Published
2011
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243. The genome of the simian and human malaria parasite Plasmodium knowlesi

Author

Pain, A., primary, Böhme, U., additional, Berry, A. E., additional, Mungall, K., additional, Finn, R. D., additional, Jackson, A. P., additional, Mourier, T., additional, Mistry, J., additional, Pasini, E. M., additional, Aslett, M. A., additional, Balasubrammaniam, S., additional, Borgwardt, K., additional, Brooks, K., additional, Carret, C., additional, Carver, T. J., additional, Cherevach, I., additional, Chillingworth, T., additional, Clark, T. G., additional, Galinski, M. R., additional, Hall, N., additional, Harper, D., additional, Harris, D., additional, Hauser, H., additional, Ivens, A., additional, Janssen, C. S., additional, Keane, T., additional, Larke, N., additional, Lapp, S., additional, Marti, M., additional, Moule, S., additional, Meyer, I. M., additional, Ormond, D., additional, Peters, N., additional, Sanders, M., additional, Sanders, S., additional, Sargeant, T. J., additional, Simmonds, M., additional, Smith, F., additional, Squares, R., additional, Thurston, S., additional, Tivey, A. R., additional, Walker, D., additional, White, B., additional, Zuiderwijk, E., additional, Churcher, C., additional, Quail, M. A., additional, Cowman, A. F., additional, Turner, C. M. R., additional, Rajandream, M. A., additional, Kocken, C. H. M., additional, Thomas, A. W., additional, Newbold, C. I., additional, Barrell, B. G., additional, and Berriman, M., additional

Published
2008
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