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fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
Aad, G.; Perez, K. (2012)
Publisher: Elsevier
Types: Article
Subjects: QA, QC
This Letter presents evidence for the associated production of a W boson and a top quark using 2.05 fb^(−1) of pp collision data at √s = 7 TeV accumulated with the ATLAS detector at the LHC. The analysis is based on the selection of the dileptonic final states with events featuring two isolated leptons, electron or muon, with significant transverse missing momentum and at least one jet. An approach based on boosted decision trees has been developed to improve the discrimination of single top-quark Wt events from background. A template fit to the final classifier distributions is performed to determine the cross-section. The result is incompatible with the background-only hypothesis at the 3.3σ level, the expected sensitivity assuming the Standard Model production rate being 3.4σ. The corresponding cross-section is determined and found to be σ_(Wt) = 16.8±2.9 (stat)±4.9 (syst) pb, in good agreement with the Standard Model expectation. From this result the CKM matrix element |V_(tb)| = 1.03^(+0.16)_(−0.19) is derived assuming that the Wt production through |V_(ts)| and |V_(td)| is small.
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • [1] D0 Collaboration, V.M. Abazov, et al., Phys. Rev. Lett. 103 (2009) 092001.
    • [2] CDF Collaboration, T. Aaltonen, et al., Phys. Rev. Lett. 103 (2009) 092002.
    • [3] ATLAS Collaboration, Phys. Lett. B (2012), submitted for publication, arXiv:1205.3130 [hep-ex].
    • [4] CMS Collaboration, Phys. Rev. Lett. 107 (2011) 091802.
    • [5] N. Kidonakis, Phys. Rev. D 82 (2010) 054018.
    • [6] T.M.P. Tait, C.P. Yuan, Phys. Rev. D 63 (2000) 014018.
    • [7] N. Cabibbo, Phys. Rev. Lett. 10 (1963).
    • [8] M. Kobayashi, T. Maskawa, Prog. Theor. Phys. 49 (1973).
    • [9] ATLAS Collaboration, J. Inst. 3 (2008) S08003.
    • [10] ATLAS Collaboration, Eur. Phys. J. C 71 (2011) 1630.
    • [11] ATLAS Collaboration, Luminosity determination in pp collision at 7 TeV using the ATLAS detector at the LHC in 2011, ATLAS-CONF-2011-116 (2011), https://cdsweb.cern.ch/record/1376384.
    • [12] Tevatron Electroweak Working Group for CDF Collaboration and D0 Collaboration, Combination of CDF and D0 results on the mass of the top quark using up to 5.8 fb−1 of data, arXiv:1107.5255 [hep-ex].
    • [13] B.P. Kersevan, E. Richter-Was, The Monte Carlo event generator AcerMC version 2.0 with interfaces to PYTHIA 6.2 and HERWIG 6.5, hep-ph/0405247.
    • [14] A. Sherstnev, R. Thorne, Eur. Phys. J. C 55 (2008) 553.
    • [15] S. Frixione, B.R. Webber, P. Nason, MC@NLO Generator version 3.4, hep-ph/ 0204244, hep-ph/0305252, 2002.
    • [16] P.M. Nadolsky, H.-L. Lai, Q.-H. Cao, J. Huston, J. Pumplin, Phys. Rev. D 78 (2008) 013004.
    • [17] S. Moch, P. Uwer, Nucl. Phys. Proc. Suppl. 183 (2008) 75.
    • [18] U. Langenfeld, S. Moch, P. Uwer, New results for tt¯ production at hadron colliders, arXiv:0907.2527 [hep-ph], 2009.
    • [19] M. Beneke, et al., Phys. Lett. B 690 (2010) 483. Predictions in the Letter are calculated with Hathor [43] to compute approximate NNLO cross sections with mtop = 172.5 GeV and CTEQ66 [44].
    • [20] M.L. Mangano, M. Moretti, F. Piccinini, R. Pittau, A.D. Polosa, JHEP 0307 (2003) 001.
    • [21] H.-L. Lai, M. Guzzi, J. Huston, Z. Li, P.M. Nadolsky, Phys. Rev. D 82 (2010) 074024.
    • [22] G. Corcella, et al., JHEP 0101 (2001) 010.
    • [23] J.M. Butterworth, J.R. Forshaw, M.H. Seymour, Z. Phys. C 72 (1996) 637.
    • [24] ATLAS Collaboration, Eur. Phys. J. C 70 (2010) 823.
    • [25] GEANT4 Collaboration, S. Agostinelli, et al., Nucl. Instrum. Methods A 506 (2003) 250.
    • [26] ATLAS Collaboration, Data-quality requirements and event cleaning for jets and missing transverse energy reconstruction with the ATLAS detector in protonproton collisions at a center-of-mass energy of √s = 7 TeV, ATLAS-CONF-2010- 038 (2010), https://cdsweb.cern.ch/record/1277678.
    • [27] ATLAS Collaboration, Eur. Phys. J. C 72 (2012) 1909.
    • [28] ATLAS Collaboration, JHEP 1012 (2010) 060.
    • [29] W. Lampl, et al., Calorimeter clustering algorithm: description and performance, ATL-LARG-PUB-2008-002 (2008), https://cdsweb.cern.ch/record/ 1099735.
    • [30] M. Cacciari, G.P. Salam, G. Soyez, JHEP 0804 (2008) 63.
    • [31] ATLAS Collaboration, Eur. Phys. J. C (2011), submitted for publication, arXiv: 1112.6426 [hep-ex].
    • [32] ATLAS Collaboration, Eur. Phys. J. C 72 (2012) 1844.
    • [33] ATLAS Collaboration, Eur. Phys. J. C 71 (2011) 1577.
    • [34] L. Breiman, J. Friedman, R. Olshen, C. Stone, Classification and Regression Trees, Wadsworth Inc., 1984.
    • [35] A. Hoecker, et al., PoS ACAT (2007) 040, physics/0703039.
    • [36] T. Sjostrand, S. Mrenna, P. Skands, JHEP 0605 (2006) 026.
    • [37] ATLAS Collaboration, Eur. Phys. J. C 72 (2012) 2043.
    • [38] A. Martin, W. Stirling, R. Thorne, G. Watt, Eur. Phys. J. C 64 (2009) 653.
    • [39] R.D. Ball, L. Del Debbio, S. Forte, A. Guffanti, J.I. Latorre, Nucl. Phys. B 838 (2010) 136.
    • [40] W. Verkerke, EPJ Web of Conferences 4 (2010) 02005.
    • [41] G. Cowan, K. Cranmer, E. Gross, O. Vitells, Eur. Phys. J. C 71 (2011) 1554.
    • [42] Tevatron Electroweak Working Group for CDF Collaboration and D0 Collaboration, Combination of CDF and D0 measurements of the single top production cross section, arXiv:0908.2171 [hep-ex].
    • [43] M. Aliev, et al., Comput. Phys. Commun. 182 (2011) 1034.
    • [44] J. Pumplin, et al., JHEP 0207 (2002) 012.
    • 165 Department of Physics, University of Illinois, Urbana IL, United States
    • 166 Department of Physics and Astronomy, University of Uppsala, Uppsala, Sweden
    • 167 Instituto de Física Corpuscular (IFIC) and Departamento de Física Atómica, Molecular y Nuclear and Departamento de Ingeniería Electrónica and Instituto de Microelectrónica de Barcelona (IMB-CNM), University of Valencia and CSIC, Valencia, Spain
    • 168 Department of Physics, University of British Columbia, Vancouver BC, Canada
    • 169 Department of Physics and Astronomy, University of Victoria, Victoria BC, Canada
    • 170 Department of Physics, University of Warwick, Coventry, United Kingdom
    • 171 Waseda University, Tokyo, Japan
    • 172 Department of Particle Physics, The Weizmann Institute of Science, Rehovot, Israel
    • 173 Department of Physics, University of Wisconsin, Madison WI, United States
    • 174 Fakultät für Physik und Astronomie, Julius-Maximilians-Universität, Würzburg, Germany
    • 175 Fachbereich C Physik, Bergische Universität Wuppertal, Wuppertal, Germany
    • 176 Department of Physics, Yale University, New Haven CT, United States
    • 177 Yerevan Physics Institute, Yerevan, Armenia
    • 178 Domaine scientifique de la Doua, Centre de Calcul CNRS/IN2P3, Villeurbanne Cedex, France
    • v Also at CPPM, Aix-Marseille Université and CNRS/IN2P3, Marseille, France.
    • ag Also at LAL, Université Paris-Sud and CNRS/IN2P3, Orsay, France.
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