Evidence for the associated production of a W boson and a top quark in ATLAS at √s=7TeV

G Aad; B Abbott; J Abdallah; S Abdel Khalek; AA Abdelalim; O Abdinov; B Abi; M Abolins; OS AbouZeid; H Abramowicz; H Abreu; E Acerbi; BS Acharya; L Adamczyk; DL Adams; TN Addy; J Adelman; S Adomeit; P Adragna; T Adye; S Aefsky; JA Aguilar-Saavedra; M Aharrouche; SP Ahlen; F Ahles; A Ahmad; M Ahsan; G Aielli; T Akdogan; TPA Åkesson; G Akimoto; AV Akimov; A Akiyama; MS Alam; MA Alam; J Albert; S Albrand; M Aleksa; IN Aleksandrov; F Alessandria; C Alexa; G Alexander; G Alexandre; T Alexopoulos; M Alhroob; M Aliev; G Alimonti; J Alison; BMM Allbrooke; PP Allport; SE Allwood-Spiers; J Almond; A Aloisio; R Alon; A Alonso; B Alvarez Gonzalez; MG Alviggi; K Amako; C Amelung; VV Ammosov; A Amorim; N Amram; C Anastopoulos; LS Ancu; N Andari; T Andeen; CF Anders; G Anders; KJ Anderson; A Andreazza; V Andrei; XS Anduaga; A Angerami; F Anghinolfi; A Anisenkov; N Anjos; A Annovi; A Antonaki; M Antonelli; A Antonov; J Antos; F Anulli; S Aoun; L Aperio Bella; R Apolle; G Arabidze; I Aracena; Y Arai; ATH Arce; S Arfaoui; JF Arguin; E Arik; M Arik; AJ Armbruster; O Arnaez; V Arnal; C Arnault; A Artamonov; G Artoni; D Arutinov

Journal article

Evidence for the associated production of a W boson and a top quark in ATLAS at √s=7TeV

G Aad, B Abbott, J Abdallah, S Abdel Khalek, AA Abdelalim, O Abdinov, B Abi, M Abolins, OS AbouZeid, H Abramowicz, H Abreu, E Acerbi, BS Acharya, L Adamczyk, DL Adams, TN Addy, J Adelman, S Adomeit, P Adragna, T Adye Show all

Physics Letters Section B Nuclear Elementary Particle and High Energy Physics | Published : 2012

DOI: 10.1016/j.physletb.2012.08.011

Open access

Abstract

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=7TeV 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 leve..

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University of Melbourne Researchers

Nadia Davidson Author

Anna Phan Author

Martin Sevior Author

Elisabetta Barberio Author

Grants

Awarded by Departamento Administrativo de Ciencia, Tecnología e Innovación (COLCIENCIAS)

Funding Acknowledgements

We acknowledge the support of ANPCyT, Argentina; YerPhl, Armenia; ARC, Australia; BMWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; CONICYT, Chile; CAS, MOST and NSFC, China; COLCIENCIAS, Colombia; MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF, DNSRC and Lundbeck Foundation, Denmark; EPLANET and ERC, European Union; IN2P3-CNRS, CEA-DSM/IRFU, France; GNAS, Georgia; BMBF, DFG, HGF, MPG and AvH Foundation, Germany; GSRT, Greece; ISF, MINERVA, GIF, DIP and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; FOM and NWO, Netherlands; RCN, Norway; MNiSW, Poland; GRICES and FCT, Portugal; MERYS (MECTS), Romania; MES of Russia and ROSATOM, Russian Federation; JINR; MSTD, Serbia; MSSR, Slovakia; ARRS and MVZT, Slovenia; DST/NRF, South Africa; MICINN, Spain; SRC and Wallenberg Foundation, Sweden; SER, SNSF and Cantons of Bern and Geneva, Switzerland; NSC, Taiwan; TAEK, Turkey; STFC, the Royal Society and Leverhulme Trust, United Kingdom; DOE and NSF, United States of America.