| Thème(s) : |
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Physique/Physique des Hautes Energies - Expérience
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| Titre : |
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Measurement of Leptonic Asymmetries and Top Quark Polarization in ttbar Production |
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| Auteur : |
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V.M. Abazov, H. Li1, G. Sajot1, J. Stark1, S. Greder2, F. Miconi2, I. Ripp-Baudot2, U. Bassler3, G. Bernardi4, M. Besançon3, D. Brown4, J. Brown4, E. Chapon3, S. Chevalier-Tthéry3, F. Couderc3, A. Croc3, F. Déliot3, C. Deterre3, Y. Enari4, G. Grenier5, A. Grohsjean3, Z. Hubacek3, T. Kurca5, P. Lebrun5, J. Lellouch4, R. Madar3, C. Royon3, V. Shary3, M. Titov3, B. Tuchming3, P. Verdier5, D. Vilanova3, M. C. Cousinou6, A. Duperrin6, W. Geng6, E. Kajfasz6, S. Kermiche6, E. Nagy6, N. Osman6, F. Badaud7, P. Gay7, Ph. Gris7, J.-F. Grivaz8, T. Guillemin8, M. Jaffré8, P. Pétroff8 |
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| Laboratoire : |
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| Résumé : |
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We present measurements of lepton (l) angular distributions in ttbar -> W+ b W- b -> l+ nu b l- nubar bbar decays produced in ppbar collisions at a center-of-mass energy of sqrt(s)=1.96TeV, where l is an electron or muon. Using data corresponding to an integrated luminosity of 5.4fb^-1, collected with the D0 detector at the Fermilab Collider, we find that the angular distributions of l- relative to anti-protons and l+ relative to protons are in agreement with each other. Combining the two distributions and correcting for detector acceptance we obtain the forward-backward asymmetry A^l_FB = (5.8 +- 5.1(stat) +- 1.3(syst))%, compared to the standard model prediction of A^l_FB (predicted) = (4.7 +- 0.1)%. This result is further combined with the measurement based on the analysis of the l+jets final state to obtain A^l_FB = (11.8 +- 3.2)%. Furthermore, we present a first study of the top-quark polarization. |
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| Collaboration/Projet : |
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D0 |
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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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2013 |
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| Nom du périodique : |
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| Physical Review D (Phys. Rev. D) |
| Publisher |
American Physical Society |
| ISSN |
1550-7998 (eISSN : 1550-2368) |
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| Volume : |
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87 |
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| Page/Article : |
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011103(R) |
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| Identifiant local : |
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LPSC12183 |
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| Commentaire : |
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See paper for full list of authors - submitted to Phys. Rev. Lett., 8 pages |
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