Search for anomalous couplings in the W tb vertex from the measurement of double differential angular decay rates of single top quarks produced in the t-channel with the ATLAS detector

The ATLAS collaboration

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    Abstract

    Abstract: The electroweak production and subsequent decay of single top quarks is determined by the properties of the Wtb vertex. This vertex can be described by the complex parameters of an effective Lagrangian. An analysis of angular distributions of the decay products of single top quarks produced in the t -channel constrains these parameters simultaneously. The analysis described in this paper uses 4.6 fb−1 of proton-proton collision data at (Formula presented.) TeV collected with the ATLAS detector at the LHC. Two parameters are measured simultaneously in this analysis. The fraction f1 of decays containing transversely polarised W bosons is measured to be 0.37 ± 0.07 (stat.⊕syst.). The phase δ between amplitudes for transversely and longitudinally polarised W bosons recoiling against left-handed b-quarks is measured to be −0.014π ± 0.036π (stat.⊕syst.). The correlation in the measurement of these parameters is 0.15. These values result in two-dimensional limits at the 95% confidence level on the ratio of the complex coupling parameters gR and VL, yielding Re[gR/VL] ∈ [−0.36, 0.10] and Im[gR/VL] ∈ [−0.17, 0.23] with a correlation of 0.11. The results are in good agreement with the predictions of the Standard Model.[Figure not available: see fulltext.]

    Original languageEnglish (US)
    Article number23
    JournalJournal of High Energy Physics
    Volume2016
    Issue number4
    DOIs
    StatePublished - Apr 1 2016

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    decay rates
    apexes
    quarks
    detectors
    decay
    bosons
    recoilings
    protons
    confidence
    angular distribution
    collisions
    products
    predictions

    Keywords

    • Hadron-Hadron scattering

    ASJC Scopus subject areas

    • Nuclear and High Energy Physics

    Cite this

    @article{038a057d3de14f62a6d5ffeb4511aca1,
    title = "Search for anomalous couplings in the W tb vertex from the measurement of double differential angular decay rates of single top quarks produced in the t-channel with the ATLAS detector",
    abstract = "Abstract: The electroweak production and subsequent decay of single top quarks is determined by the properties of the Wtb vertex. This vertex can be described by the complex parameters of an effective Lagrangian. An analysis of angular distributions of the decay products of single top quarks produced in the t -channel constrains these parameters simultaneously. The analysis described in this paper uses 4.6 fb−1 of proton-proton collision data at (Formula presented.) TeV collected with the ATLAS detector at the LHC. Two parameters are measured simultaneously in this analysis. The fraction f1 of decays containing transversely polarised W bosons is measured to be 0.37 ± 0.07 (stat.⊕syst.). The phase δ− between amplitudes for transversely and longitudinally polarised W bosons recoiling against left-handed b-quarks is measured to be −0.014π ± 0.036π (stat.⊕syst.). The correlation in the measurement of these parameters is 0.15. These values result in two-dimensional limits at the 95{\%} confidence level on the ratio of the complex coupling parameters gR and VL, yielding Re[gR/VL] ∈ [−0.36, 0.10] and Im[gR/VL] ∈ [−0.17, 0.23] with a correlation of 0.11. The results are in good agreement with the predictions of the Standard Model.[Figure not available: see fulltext.]",
    keywords = "Hadron-Hadron scattering",
    author = "{The ATLAS collaboration}, {ATLAS collaboration} and G. Aad and B. Abbott and J. Abdallah and O. Abdinov and R. Aben and M. Abolins and AbouZeid, {O. S.} and H. Abramowicz and H. Abreu and R. Abreu and Y. Abulaiti and Acharya, {B. S.} and L. Adamczyk and Adams, {D. L.} and J. Adelman and S. Adomeit and T. Adye and Affolder, {A. A.} and T. Agatonovic-Jovin and J. Agricola and Aguilar-Saavedra, {J. A.} and Ahlen, {S. P.} and F. Ahmadov and G. Aielli and H. Akerstedt and {\AA}kesson, {T. P A} and Akimov, {A. V.} and Alberghi, {G. L.} and J. Albert and S. Albrand and {Alconada Verzini}, {M. J.} and M. Aleksa and Aleksandrov, {I. N.} and C. Alexa and G. Alexander and T. Alexopoulos and M. Alhroob and G. Alimonti and L. Alio and J. Alison and Alkire, {S. P.} and Allbrooke, {B. M M} and Allport, {P. P.} and A. Aloisio and A. Alonso and F. Alonso and K. Cranmer and A. Haas and Mincer, {A. I.} and P. Nemethy",
    year = "2016",
    month = "4",
    day = "1",
    doi = "10.1007/JHEP04(2016)023",
    language = "English (US)",
    volume = "2016",
    journal = "Journal of High Energy Physics",
    issn = "1126-6708",
    publisher = "Springer Verlag",
    number = "4",

    }

    TY - JOUR

    T1 - Search for anomalous couplings in the W tb vertex from the measurement of double differential angular decay rates of single top quarks produced in the t-channel with the ATLAS detector

    AU - The ATLAS collaboration

    AU - Aad, G.

    AU - Abbott, B.

    AU - Abdallah, J.

    AU - Abdinov, O.

    AU - Aben, R.

    AU - Abolins, M.

    AU - AbouZeid, O. S.

    AU - Abramowicz, H.

    AU - Abreu, H.

    AU - Abreu, R.

    AU - Abulaiti, Y.

    AU - Acharya, B. S.

    AU - Adamczyk, L.

    AU - Adams, D. L.

    AU - Adelman, J.

    AU - Adomeit, S.

    AU - Adye, T.

    AU - Affolder, A. A.

    AU - Agatonovic-Jovin, T.

    AU - Agricola, J.

    AU - Aguilar-Saavedra, J. A.

    AU - Ahlen, S. P.

    AU - Ahmadov, F.

    AU - Aielli, G.

    AU - Akerstedt, H.

    AU - Åkesson, T. P A

    AU - Akimov, A. V.

    AU - Alberghi, G. L.

    AU - Albert, J.

    AU - Albrand, S.

    AU - Alconada Verzini, M. J.

    AU - Aleksa, M.

    AU - Aleksandrov, I. N.

    AU - Alexa, C.

    AU - Alexander, G.

    AU - Alexopoulos, T.

    AU - Alhroob, M.

    AU - Alimonti, G.

    AU - Alio, L.

    AU - Alison, J.

    AU - Alkire, S. P.

    AU - Allbrooke, B. M M

    AU - Allport, P. P.

    AU - Aloisio, A.

    AU - Alonso, A.

    AU - Alonso, F.

    AU - Cranmer, K.

    AU - Haas, A.

    AU - Mincer, A. I.

    AU - Nemethy, P.

    PY - 2016/4/1

    Y1 - 2016/4/1

    N2 - Abstract: The electroweak production and subsequent decay of single top quarks is determined by the properties of the Wtb vertex. This vertex can be described by the complex parameters of an effective Lagrangian. An analysis of angular distributions of the decay products of single top quarks produced in the t -channel constrains these parameters simultaneously. The analysis described in this paper uses 4.6 fb−1 of proton-proton collision data at (Formula presented.) TeV collected with the ATLAS detector at the LHC. Two parameters are measured simultaneously in this analysis. The fraction f1 of decays containing transversely polarised W bosons is measured to be 0.37 ± 0.07 (stat.⊕syst.). The phase δ− between amplitudes for transversely and longitudinally polarised W bosons recoiling against left-handed b-quarks is measured to be −0.014π ± 0.036π (stat.⊕syst.). The correlation in the measurement of these parameters is 0.15. These values result in two-dimensional limits at the 95% confidence level on the ratio of the complex coupling parameters gR and VL, yielding Re[gR/VL] ∈ [−0.36, 0.10] and Im[gR/VL] ∈ [−0.17, 0.23] with a correlation of 0.11. The results are in good agreement with the predictions of the Standard Model.[Figure not available: see fulltext.]

    AB - Abstract: The electroweak production and subsequent decay of single top quarks is determined by the properties of the Wtb vertex. This vertex can be described by the complex parameters of an effective Lagrangian. An analysis of angular distributions of the decay products of single top quarks produced in the t -channel constrains these parameters simultaneously. The analysis described in this paper uses 4.6 fb−1 of proton-proton collision data at (Formula presented.) TeV collected with the ATLAS detector at the LHC. Two parameters are measured simultaneously in this analysis. The fraction f1 of decays containing transversely polarised W bosons is measured to be 0.37 ± 0.07 (stat.⊕syst.). The phase δ− between amplitudes for transversely and longitudinally polarised W bosons recoiling against left-handed b-quarks is measured to be −0.014π ± 0.036π (stat.⊕syst.). The correlation in the measurement of these parameters is 0.15. These values result in two-dimensional limits at the 95% confidence level on the ratio of the complex coupling parameters gR and VL, yielding Re[gR/VL] ∈ [−0.36, 0.10] and Im[gR/VL] ∈ [−0.17, 0.23] with a correlation of 0.11. The results are in good agreement with the predictions of the Standard Model.[Figure not available: see fulltext.]

    KW - Hadron-Hadron scattering

    UR - http://www.scopus.com/inward/record.url?scp=84962723651&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=84962723651&partnerID=8YFLogxK

    U2 - 10.1007/JHEP04(2016)023

    DO - 10.1007/JHEP04(2016)023

    M3 - Article

    VL - 2016

    JO - Journal of High Energy Physics

    JF - Journal of High Energy Physics

    SN - 1126-6708

    IS - 4

    M1 - 23

    ER -