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 HAL : in2p3-00004624, version 1
 Physics Letters B 475 (2000) 395-406
 Fermi-Dirac Correlations in $\Lambda$ Pairs in Hadronic Z Decays
 ALEPH Collaboration(s)
 (2000)
 Two-particle correlations of Lambda Lambda and Anti-Lambda Anti-Lambda pairshave 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 Anti-Lambda 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.
 Thème(s) : Physique/Physique des Hautes Energies - Expérience
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 in2p3-00004624, version 1 http://hal.in2p3.fr/in2p3-00004624 oai:hal.in2p3.fr:in2p3-00004624 Contributeur : Nicole Berger <> Soumis le : Mardi 4 Avril 2000, 11:01:21 Dernière modification le : Jeudi 2 Juin 2005, 13:56:16