Fermi-Dirac correlations in Lambda pairs in hadronic Z decays

Authors
Barate, R Decamp, D Ghez, P Goy, C Lees, JP Martin, F Merle, E Minard, MN Pietrzyk, B Alemany, R Bravo, S Casado, MP Chmeissani, M Crespo, JM Fernandez, E Fernandez-Bosman, M Garrido, L Grauges, E Juste, A Martinez, M Merino, G Miquel, R Mir, LM Pacheco, A Riu, I Ruiz, H Colaleo, A Creanza, D de Palma, M Iaselli, G Maggi, G Maggi, M Nuzzo, S Ranieri, A Raso, G Ruggieri, F Selvaggi, G Silvestris, L Tempesta, P Tricomi, A Zito, G Huang, X Lin, J Ouyang, Q Wang, T Xie, Y Xu, R Xue, S Zhang, J Zhang, L Zhao, W Abbaneo, D Boix, G Buchmuller, O Cattaneo, M Cerutti, F Ciulli, V Dissertori, G Drevermann, H Forty, RW Frank, M Greening, TC Halley, AW Hansen, JB Harvey, J Janot, P Jost, B Lehraus, I Leroy, O Mato, P Minten, A Moutoussi, A Ranjard, F Rolandi, L Schlatter, D Schmitt, M Schneider, O Spagnolo, P Tejessy, W Teubert, F Tournefier, E Wright, AE Ajaltouni, Z Badaud, F Chazelle, G Deschamps, O Falvard, A Ferdi, C Gay, P Guicheney, C Henrard, P Jousset, J Michel, B Monteil, S Montret, JC Pallin, D Perret, P Podlyski, F Hansen, JD Hansen, JR Hansen, PH Nilsson, BS Rensch, B Waananen, A Daskalakis, G Kyriakis, A Markou, C Simopoulou, E Siotis, I Vayaki, A Blondel, A Bonneaud, G Brient, JC Rouge, A Rumpf, M Swynghedauw, M Verderi, M Videau, H Focardi, E Parrini, G Zachariadou, K Corden, M Georgiopoulos, C Antonelli, A Bencivenni, G Bologna, G Bossi, F Campana, P Capon, G Chiarella, V Laurelli, P Mannocchi, G Murtas, F Murtas, GP Passalacqua, L Pepe-Altarelli, M Curtis, L Lynch, JG Negus, P O'Shea, V Raine, C Teixeira-Dias, P Thompson, AS Cavanaugh, R Dhamotharan, S Geweniger, C Hanke, P Hansper, G Hepp, V Kluge, EE Putzer, A Sommer, J Tittel, K Werner, S Wunsch, M Beuselinck, R Binnie, DM Cameron, W Dornan, PJ Girone, M Goodsir, S Martin, EB Marinelli, N Sciaba, A Sedgbeer, JK Thomson, E Williams, MD Ghete, VM Girtler, P Kneringer, E Kuhn, D Rudolph, G Bowdery, CK Buck, PG Finch, AJ Foster, F Hughes, G Jones, RWL Robertson, NA Williams, MI Giehl, I Jakobs, K Kleinknecht, K Quast, G Renk, B Rohne, E Sander, HG Wachsmuth, H Zeitnitz, C Aubert, JJ Bonissent, A Carr, J Coyle, P Payre, P Rousseau, D Aleppo, M Antonelli, M Ragusa, F Buscher, V Dietl, H Ganis, G Huttmann, K Lutjens, G Mannert, C Manner, W Moser, HG Schael, S Settles, R Seywerd, H Stenzel, H Wiedenmann, W Wolf, G Azzurri, P Boucrot, J Callot, O Chen, S Cordier, A Davier, M Duflot, L Grivaz, JF Heusse, P Jacholkowska, A Le Diberder, F Lefrancois, J Lutz, AM Schune, MH Veillet, JJ Videau, I Zerwas, D Bagliesi, G Boccali, T Bozzi, C Calderini, G Dell'Orso, R Ferrante, I Foa, L Giassi, A Gregorio, A Ligabue, F Marrocchesi, PS Messineo, A Palla, F Rizzo, G Sanguinetti, G Sguazzoni, G Tenchini, R Venturi, A Verdini, PG Blair, GA Cowan, G Green, MG Medcalf, T Strong, JA Botterill, DR Clifft, RW Edgecock, TR Norton, PR Thompson, JC Tomalin, IR Bloch-Devaux, B Colas, P Emery, S Kozanecki, W Lancon, E Lemaire, MC Locci, E Perez, P Rander, J Renardy, JF Roussarie, A Schuller, JP Schwindling, J Trabelsi, A Vallage, B Black, SN Dann, JH Johnson, RP Kim, HY Konstantinidis, N Litke, AM McNeil, MA Taylor, G Booth, CN Cartwright, S Combley, F Lehto, M Thompson, LF Affholderbach, K Bohrer, A Brandt, S Grupen, C Hess, J Misiejuk, A Prange, G Sieler, U Giannini, G Gobbo, B Rothberg, J Wasserbaech, S Armstrong, SR Elmer, P Ferguson, DPS Gao, Y Gonzalez, S Hayes, OJ Hu, H Jin, S Kile, J McNamara, PA Nielsen, J Orejudos, W Pan, YB Saadi, Y Scott, IJ Walsh, J von Wimmersperg-Toeller, JH Wu, SL Wu, X Zobernig, G
Citation
R. Barate et al., Fermi-Dirac correlations in Lambda pairs in hadronic Z decays, PHYS LETT B, 475(3-4), 2000, pp. 395-406
Citations number
29
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICS LETTERS B
ISSN journal
0370-2693 → ACNP
Volume
475
Issue
3-4
Year of publication
2000
Pages
395 - 406
Database
ISI
SICI code
0370-2693(20000302)475:3-4<395:FCILPI>2.0.ZU;2-A
Abstract
Two-particle correlations of Lambda Lambda and <(Lambda)over bar><(Lambda)o ver bar> pairs have been studied in multihadronic Z decays recorded with th e ALEPH detector at LEP in the years from 1992 to 1995. The correlations we re measured as a function of the four-momentum difference Q of the pair. A depletion of events is observed in the region Q < 2 GeV which could arise f rom the effects of Fermi-Dirac statistics. In addition the spin content of the Lambda pair system has been determined. For Q > 2 GeV the fraction of p airs with spin one is consistent with the value of 0.75 expected for a stat istical spin mixture, whilst for Q < 2 GeV this fraction is found to be low er. For Lambda<(Lambda)over bar> pairs, where no Fermi-Dirac correlations a re expected, the spin one fraction is measured to be consistent with 0.75 o ver the entire analysed Q range. (C) 2000 Elsevier Science B.V. All rights reserved.