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

ATLAS Collaboration

doi:10.1016/j.physletb.2012.08.011

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

ATLAS Collaboration

School of Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

102 Scopus citations

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 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_−0.19 ^+0.16 is derived assuming that the Wt production through |V_ts| and |V_td| is small.

Original language	English
Pages (from-to)	142-159
Number of pages	18
Journal	Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume	716
Issue number	1
DOIs	https://doi.org/10.1016/j.physletb.2012.08.011
State	Published - 17 Sep 2012

Funding

Funders	Funder number
MECTS
Departamento Administrativo de Ciencia, Tecnología e Innovación (COLCIENCIAS)
Stichting voor Fundamenteel Onderzoek der Materie
Australian Research Council
Centre National pour la Recherche Scientifique et Technique
Fundação para a Ciência e a Tecnologia
DIP
Bundesministerium für Wissenschaft und Forschung
National Research Foundation of Korea
Comisión Nacional de Investigación Científica y Tecnológica
Healthcare Georgia Foundation
CEA-DSM
Japan Society for the Promotion of Science
GNAS
Nederlandse Organisatie voor Wetenschappelijk Onderzoek
Ministerio de Ciencia e Innovación
Ministry of Science and Technology, Taiwan
Israel Science Foundation
Wallenberg Foundation
Leverhulme Trust
Lundbeckfonden
Arizona-Nevada Academy of Science
Javna Agencija za Raziskovalno Dejavnost RS
National Science Council
Engineering Research Centers
Instituto Nazionale di Fisica Nucleare
MSTD
Department of Science and Technology, Ministry of Science and Technology, India
MSMT
Türkiye Atom Enerjisi Kurumu
MSSR
Max-Planck-Gesellschaft
Bundesministerium für Bildung und Forschung
Canada Foundation for Innovation
MVZT
Danmarks Grundforskningsfond
Conselho Nacional de Desenvolvimento Científico e Tecnológico
Czech Republic
Deutsche Forschungsgemeinschaft
U.S. Department of Energy
National Research Council
Fundação de Amparo à Pesquisa do Estado de São Paulo
MES of Russia
State Atomic Energy Corporation ROSATOM
Natural Sciences and Engineering Research Council of Canada
General Secretariat for Research and Technology
Nella and Leon Benoziyo Center for Neurological Diseases, Weizmann Institute of Science
MERYS
School of Energy Resources, University of Wyoming
DNSRC
German-Israeli Foundation for Scientific Research and Development
Cantons of Bern and Geneva
Chinese Academy of Sciences
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
VSC CR
Agencia Nacional de Promoción Científica y Tecnológica
Royal Society
Minerva Foundation
Ministerstwo Nauki i Szkolnictwa Wyższego
IRFU
CERN
Joint Institute for Nuclear Research
Alexander von Humboldt-Stiftung
Council on grants of the President of the Russian Federation
Ministry of Education, Culture, Sports, Science and Technology
National Natural Science Foundation of China
European Commission	IN2P3-CNRS, 246806
Science and Technology Facilities Council	ST/F007337/1, PP/E002757/1, ST/I005803/1, ST/J004944/1, ST/I003142/1, ST/H001069/2, PP/E000347/1, ST/K501840/1, ST/L001195/1, ST/H001026/1, ST/H001042/1, ST/I006080/1, ST/H001042/2, ST/I000186/1, ST/J004928/1, ST/K001361/1, ST/I003517/1, GRIDPP, ST/G502320/1, ST/K001310/1, ST/K001337/1, ST/H00100X/1, ST/L001144/1, ST/K00073X/1, ST/J002798/1, ST/H00100X/2, ST/K000705/1, ST/K001248/1, ST/I005811/1, ST/M000761/1, ST/J005460/1, PP/E003087/1, PP/E000355/1, ST/M001431/1, ST/H001093/2, ST/K001418/1, ST/M001474/1, ST/K00140X/1, ST/H001093/1, ST/I003525/1, ST/M001512/1, ST/H001026/2, PP/E003699/2, PP/E003699/1, ST/J005576/1
National Science Foundation	1119200

Keywords

ATLAS
Single top-quark
Top quark
W+t

Access to Document

10.1016/j.physletb.2012.08.011

Cite this

@article{7b8e311fc3744667b4353804cdcff142,

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

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 level, the expected sensitivity assuming the Standard Model production rate being 3.4σ. The corresponding cross-section is determined and found to be σWt=16.8±2.9 (stat)±4.9 (syst) pb, in good agreement with the Standard Model expectation. From this result the CKM matrix element |Vtb|=1.03−0.19 +0.16 is derived assuming that the Wt production through |Vts| and |Vtd| is small.",

keywords = "ATLAS, Single top-quark, Top quark, W+t",

author = "{ATLAS Collaboration} and G. Aad and B. Abbott and J. Abdallah and {Abdel Khalek}, S. and Abdelalim, {A. A.} and O. Abdinov and B. Abi and M. Abolins and AbouZeid, {O. S.} and H. Abramowicz and H. Abreu and E. Acerbi and Acharya, {B. S.} and L. Adamczyk and Adams, {D. L.} and Addy, {T. N.} and J. Adelman and S. Adomeit and P. Adragna and T. Adye and S. Aefsky and Aguilar-Saavedra, {J. A.} and M. Aharrouche and Ahlen, {S. P.} and F. Ahles and A. Ahmad and M. Ahsan and G. Aielli and T. Akdogan and {\AA}kesson, {T. P.A.} and G. Akimoto and Akimov, {A. V.} and A. Akiyama and Alam, {M. S.} and Alam, {M. A.} and J. Albert and S. Albrand and M. Aleksa and Aleksandrov, {I. N.} and F. Alessandria and C. Alexa and G. Alexander and G. Alexandre and L. Barak and G. Bella and Y. Benhammou and E. Etzion and Y. Oren and Y. Silver and A. Soffer",

note = "Publisher Copyright: {\textcopyright} 2012 CERN",

year = "2012",

month = sep,

day = "17",

doi = "10.1016/j.physletb.2012.08.011",

language = "אנגלית",

volume = "716",

pages = "142--159",

journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",

issn = "0370-2693",

publisher = "Elsevier B.V.",

number = "1",

}

TY - JOUR

T1 - Evidence for the associated production of a W boson and a top quark in ATLAS at √s=7TeV

AU - ATLAS Collaboration

AU - Aad, G.

AU - Abbott, B.

AU - Abdallah, J.

AU - Abdel Khalek, S.

AU - Abdelalim, A. A.

AU - Abdinov, O.

AU - Abi, B.

AU - Abolins, M.

AU - AbouZeid, O. S.

AU - Abramowicz, H.

AU - Abreu, H.

AU - Acerbi, E.

AU - Acharya, B. S.

AU - Adamczyk, L.

AU - Adams, D. L.

AU - Addy, T. N.

AU - Adelman, J.

AU - Adomeit, S.

AU - Adragna, P.

AU - Adye, T.

AU - Aefsky, S.

AU - Aguilar-Saavedra, J. A.

AU - Aharrouche, M.

AU - Ahlen, S. P.

AU - Ahles, F.

AU - Ahmad, A.

AU - Ahsan, M.

AU - Aielli, G.

AU - Akdogan, T.

AU - Åkesson, T. P.A.

AU - Akimoto, G.

AU - Akimov, A. V.

AU - Akiyama, A.

AU - Alam, M. S.

AU - Alam, M. A.

AU - Albert, J.

AU - Albrand, S.

AU - Aleksa, M.

AU - Aleksandrov, I. N.

AU - Alessandria, F.

AU - Alexa, C.

AU - Alexander, G.

AU - Alexandre, G.

AU - Barak, L.

AU - Bella, G.

AU - Benhammou, Y.

AU - Etzion, E.

AU - Oren, Y.

AU - Silver, Y.

AU - Soffer, A.

PY - 2012/9/17

Y1 - 2012/9/17

N2 - 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 level, the expected sensitivity assuming the Standard Model production rate being 3.4σ. The corresponding cross-section is determined and found to be σWt=16.8±2.9 (stat)±4.9 (syst) pb, in good agreement with the Standard Model expectation. From this result the CKM matrix element |Vtb|=1.03−0.19 +0.16 is derived assuming that the Wt production through |Vts| and |Vtd| is small.

AB - 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 level, the expected sensitivity assuming the Standard Model production rate being 3.4σ. The corresponding cross-section is determined and found to be σWt=16.8±2.9 (stat)±4.9 (syst) pb, in good agreement with the Standard Model expectation. From this result the CKM matrix element |Vtb|=1.03−0.19 +0.16 is derived assuming that the Wt production through |Vts| and |Vtd| is small.

KW - ATLAS

KW - Single top-quark

KW - Top quark

KW - W+t

UR - http://www.scopus.com/inward/record.url?scp=85042037870&partnerID=8YFLogxK

U2 - 10.1016/j.physletb.2012.08.011

DO - 10.1016/j.physletb.2012.08.011

M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???

AN - SCOPUS:85042037870

SN - 0370-2693

VL - 716

SP - 142

EP - 159

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

IS - 1

ER -

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

Abstract

Funding

Keywords

Access to Document

Other files and links

Fingerprint

Cite this