Measurement of the average polarization of b baryons in hadronic Z(0) decays

Authors
Abbiendi, G Ackerstaff, K Alexander, G Allison, J Altekamp, N Anderson, KJ Anderson, S Arcelli, S Asai, S Ashby, SF Axen, D Azuelos, G Ball, AH Barberio, E Barlow, RJ Bartoldus, R Batley, JR Baumann, S Bechtluft, J Behnke, T Bell, KW Bella, G Bellerive, A Bentvelsen, S Bethke, S Betts, S Biebel, O Biguzzi, A Bird, SD Blobel, V Bloodworth, IJ Bobinski, M Bock, P Bohme, J Bonacorsi, D Boutemeur, M Braibant, S Bright-Thomas, P Brigliadori, L Brown, RM Burckhart, HJ Burgard, C Burgin, R 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 Couyoumtzelis, C Coxe, RL Cuffiani, M Dado, S Dallavalle, GM Davis, R De Jong, S del Pozo, LA de Roeck, A Desch, K Dienes, B Dixit, MS Dubbert, J Duchovni, E Duckeck, G Duerdoth, IP Eatough, D Estabrooks, PG Etzion, E Evans, HG Fabbri, F Fanti, M Faust, AA Fiedler, F Fierro, M Fleck, I Folman, R Furtjes, A Futyan, DI Gagnon, P Gary, JW Gascon, J Gascon-Shotkin, SM Gaycken, G Geich-Gimbel, C Giacomelli, G Giacomelli, P Gibson, V Gibson, WR Gingrich, DM Glenzinski, D Goldberg, J Gorn, W Grandi, C Gross, E Grunhaus, J Gruwe, M Hanson, GG Hansroul, M Hapke, M Harder, K Hargrove, CK Hartmann, C Hauschild, M Hawkes, CM Hawkings, R Hemingway, RJ Herndon, M Herten, G Heuer, RD Hildreth, MD Hill, JC Hillier, SJ Hobson, PR Hocker, A Homer, RJ Honma, AK Horvath, D Hosain, KR Howard, R Huntemeyer, P Igo-Kemenes, P Imrie, DC Ishii, K Jacob, FR Jawahery, A Jeremie, H Jimack, M Jones, CR Jovanovic, P Junk, TR Karlen, D Kartvelishvili, V Kawagoe, K Kawamoto, T Kayal, PI Keeler, RK Kellogg, RG Kennedy, BW Klier, A Kluth, S Kobayashi, T Kobel, M Koetke, DS Kokott, TP Kolrep, M Komamiya, S Kowalewski, RV Kress, T Krieger, P von Krogh, J Kuhl, T Kyberd, P Lafferty, GD Lanske, D Lauber, J Lautenschlager, SR Lawson, I Layter, JG Lazic, D Lee, AM Lellouch, D Letts, J Levinson, L Liebisch, R List, B Littlewood, C Lloyd, AW Lloyd, SL Loebinger, FK Long, GD Losty, MJ Ludwig, J Liu, D Macchiolo, A Macpherson, A Mader, W Mannelli, M Marcellini, S Markopoulos, C Martin, AJ Martin, JP Martinez, G Mashimo, T Mattig, P McDonald, WJ McKenna, J Mckigney, EA McMahon, TJ McPherson, RA Meijers, F Menke, S Merritt, FS Mes, H Meyer, J Michelini, A Mihara, S Mikenberg, G Miller, DJ Mir, R Mohr, W Montanari, A Mori, T Nagai, K Nakamura, I Neal, HA Nellen, B Nisius, R O'Neale, SW Oakham, FG Odorici, F Ogren, HO Oreglia, MJ Orito, S Palinkas, J Pasztor, G Pater, JR Patrick, GN Patt, J Perez-Ochoa, R Petzold, S Pfeifenschneider, P Pilcher, JE Pinfold, J Plane, DE Poffenberger, P Polok, J Przybycien, M Rembser, C Rick, H Robertson, S Robins, SA Rodning, N Roney, JM Roscoe, K Rossi, AM Rozen, Y Runge, K Runolfsson, O Rust, DR Sachs, K Saeki, T Sahr, O Sang, WM Sarkisyan, EKG Sbarra, C Schaile, AD Schaile, O Scharf, F Scharff-Hansen, P Schieck, J Schmitt, B Schmitt, S Schoning, A Schroder, M Schumacher, M Schwick, C Scott, WG Seuster, R Shears, TG Shen, BC Shepherd-Themistocleous, CH Sherwood, P Siroli, GP Sittler, A Skuja, A Smith, AM Snow, GA Sobie, R Soldner-Rembold, S Sproston, M Stahl, A Stephens, K Steuerer, J Stoll, K Strom, D Strohmer, R Surrow, B Talbot, SD Tanaka, S Taras, P Tarem, S Teuscher, R Thiergen, M Thomson, MA von Torne, E Torrence, E Towers, S Trigger, I Trocsanyi, Z Tsur, E Turcot, AS Turner-Watson, MF Van Kooten, R Vannerem, P Verzocchi, M Voss, H Wackerle, F Wagner, A Ward, CP Ward, DR Watkins, PM Watson, AT Watson, NK Wells, PS Wermes, N White, JS Wilson, GW Wilson, JA Wyatt, TR Yamashita, S Yekutieli, G Zacek, V Zer-Zion, D
Citation
G. Abbiendi et al., Measurement of the average polarization of b baryons in hadronic Z(0) decays, PHYS LETT B, 444(3-4), 1998, pp. 539-554
Citations number
53
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICS LETTERS B
ISSN journal
0370-2693 → ACNP
Volume
444
Issue
3-4
Year of publication
1998
Pages
539 - 554
Database
ISI
SICI code
0370-2693(199812)444:3-4<539:MOTAPO>2.0.ZU;2-Q
Abstract
In the Standard Model, b quarks produced in e(+)e(-) annihilation at the Z( 0) peak have a large average longitudinal polarization of -0.94. Some fract ion of this polarization is expected to be transferred to b-flavored baryon s during hadronization. The average longitudinal polarization of weakly dec aying b baryons, [P-L(Lambda b)], is measured in approximately 4.3 million hadronic Z(0) decays collected with the OPAL detector between 1990 and 1995 at LEP. Those b baryons that decay semileptonically and produce a Lambda b aryon are identified through the correlation of the baryon number of the La mbda and the electric charge of the lepton. In this semileptonic decay, the ratio of the neutrino energy to the lepton energy is a sensitive polarizat ion observable. The neutrino energy is estimated using missing energy measu rements. From a fit to the distribution of this ratio, the value [p(L)(Lamb da b)] = -0.56(-0.13)(+0.20) +/- 0.09 is obtained, where the first error is statistical and the second systematic. (C) 1998 Elsevier Science B.V. All rights reserved.