| Thème(s) : |
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Physique/Physique des Hautes Energies - Expérience
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| Titre : |
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Observation of spin correlation in ttbar events from pp collisions at sqrt(s) = 7 TeV using the ATLAS detector |
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| Auteur : |
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G. Aad, S. Albrand1, M.L. Andrieux1, Q. Buat1, B. Clement1, J. Collot1, S. Crépé-Renaudin1, B. Dechenaux1, T. Delemontex1, P.A. Delsart1, M.H. Genest1, J.Y. Hostachy1, E. Laisne1, F. Ledroit-Guillon1, A. Lleres1, A. Lucotte1, F. Malek1, P. Martin1, F. Polci1, J. Stark1, X. Sun1, B. Trocmé1, J. Wang1, C. Weydert1, C. Biscarat2, E. Cogneras2, G. Rahal2, D. Boumediene3, E. Busato3, D. Calvet3, S. Calvet3, R. Camacho Toro3, D. Cinca3, J. Donini3, R. Febbraro3, N. Ghodbane3, C. Guicheney3, H. Liao3, D. Pallin3, D. Paredes Hernandez3, F. Podlyski3, C. Santoni3, L.-P. Says3, F. Vazeille3, S. Abdel Khalek4, H. Abreu4, N. Andari4, C. Arnault4, E. Augé4, P. Barrillon4, M. Benoit4, S. Binet4, C. Bourdarios4, C. de La Taille4, J.B. De Vivie De Regie4, L. Duflot4, M. Escalier4, L. Fayard4, D. Fournier4, J.-F. Grivaz4, S. Henrot-Versillé4, J. Hrivnac4, L. Iconomidou-Fayard4, J. Idarraga4, M. Kado4, N. Lorenzo Martinez4, A. Lounis4, N. Makovec4, P. Matricon4, F. Niedercorn4, L. Poggioli4, P. Puzo4, A. Renaud4, D. Rousseau4, G. Rybkin4, J.B. Sauvan4, J. Schaarschmidt4, A.C. Schaffer4, E. Scifo4, L. Serin4, S. Simion4, R. Tanaka4, M. Teinturier4, J.J. Veillet4, I. Vukotic4, F. Wicek4, D. Zerwas4, Z. Zhang4, L. Aperio Bella5, B. Aubert5, N. Berger5, J. Colas, M. Delmastro5, L. Di Ciaccio5, T.K.O. Doan5, S. Elles5, C. Goy5, L. Helary5, T. Hryn'Ova5, A. Jérémie5, S. Jézéquel5, M. Kataoka5, J. Labbe5, R. Lafaye5, J. Leveque5, V.P. Lombardo5, N. Massol5, P. Perrodo5, E. Petit5, H. Przysiezniak5, E. Richter-Was5, G. Sauvage5, E. Sauvan5, M. Schwoerer5, T. Todorov5, D. Tsionou5, I. Wingerter-Seez5, R. Zitoun5, Y. Zolnierowski5, S. Aoun6, C. P. Bee6, C. Benchouk6, C. Bertella6, N. Bousson6, J. C. Clémens6, Y. Coadou6, F. Djama6, F. Etienne6, L. Feligioni6, F. Henry-Couannier6, D. Hoffmann6, F. Hubaut6, E. B. F. G. Knoops6, E. Le Guirriec6, B. Li6, J. Maurer6, E. Monnier6, J. Odier6, P. Pralavorio6, Z. Qian6, A. Rozanov6, M. Talby6, N. Tannoury6, S. Tisserant6, J. Toth6, F. Touchard6, L. Vacavant6, F. Vannucci7, 8 |
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| Laboratoire : |
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| équipe(s) de recherche : |
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APC - Neutrinos |
| Résumé : |
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A measurement of spin correlation in ttbar production is reported using data collected with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 2.1 fb^-1. Candidate events are selected in the dilepton topology with large missing transverse energy and at least two jets. The difference in azimuthal angle between the two charged leptons in the laboratory frame is used to extract the correlation between the top and antitop quark spins. In the helicity basis the measured degree of correlation corresponds to 0.40 +0.09 -0.08, in agreement with the next-to-leading-order Standard Model prediction. The hypothesis of zero spin correlation is excluded at 5.1 standard deviations. |
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| Collaboration/Projet : |
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ATLAS |
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| Type de publication : |
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Articles dans des revues avec comité de lecture |
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Date de publication ou d'écriture : |
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2012 |
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| Nom du périodique : |
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| Physical Review Letters (Phys. Rev. Lett.) |
| Publisher |
American Physical Society |
| ISSN |
0031-9007 (eISSN : 1079-7114) |
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| Volume : |
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108 |
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| Page/Article : |
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212001 |
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| Identifiant local : |
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LPSC12071 |
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| Commentaire : |
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See paper for full list of authors - 6 pages plus author list (20 pages total), 2 figures, 2 tables, submitted to Physical Review Letters |
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