Two-particle correlations of Lambda Lambda and <(Lambda)over bar><(Lambda)over bar> pairs have been studied in multihadronic Z decays recorded with the ALEPH detector at LEP in the years from 1992 to 1995. The correlations were 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 from 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 pairs with spin one is consistent with the value of 0.75 expected for a statistical spin mixture, whilst for Q < 2 GeV this fraction is found to be lower. For Lambda<(Lambda)over bar> pairs, where no Fermi-Dirac correlations are expected, the spin one fraction is measured to be consistent with 0.75 over the entire analysed Q range. (C) 2000 Elsevier Science B.V. All rights reserved.

Fermi-Dirac correlations in Lambda pairs in hadronic Z decays

FERRANTE, ISIDORO;MESSINEO, ALBERTO MARIA;RIZZO, GIULIANA;
2000

Abstract

Two-particle correlations of Lambda Lambda and <(Lambda)over bar><(Lambda)over bar> pairs have been studied in multihadronic Z decays recorded with the ALEPH detector at LEP in the years from 1992 to 1995. The correlations were 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 from 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 pairs with spin one is consistent with the value of 0.75 expected for a statistical spin mixture, whilst for Q < 2 GeV this fraction is found to be lower. For Lambda<(Lambda)over bar> pairs, where no Fermi-Dirac correlations are expected, the spin one fraction is measured to be consistent with 0.75 over the entire analysed Q range. (C) 2000 Elsevier Science B.V. All rights reserved.
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, Isidoro; Foa, L; Giassi, A; Gregorio, A; Ligabue, F; Marrocchesi, Ps; Messineo, ALBERTO MARIA; Palla, F; Rizzo, Giuliana; 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.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11568/161886
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