Measurement of the charge asymmetry in highly boosted top-quark pair production in √s=8 TeV pp collision data collected by the ATLAS experiment

ATLAS Collaboration

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    16 Citations (Scopus)

    Abstract

    In the pp→tt¯ process the angular distributions of top and anti-top quarks are expected to present a subtle difference, which could be enhanced by processes not included in the Standard Model. This Letter presents a measurement of the charge asymmetry in events where the top-quark pair is produced with a large invariant mass. The analysis is performed on 20.3 fb−1 of pp collision data at s=8TeV collected by the ATLAS experiment at the LHC, using reconstruction techniques specifically designed for the decay topology of highly boosted top quarks. The charge asymmetry in a fiducial region with large invariant mass of the top-quark pair (mtt¯>0.75 TeV) and an absolute rapidity difference of the top and anti-top quark candidates within −2<|yt|−|y|<2 is measured to be 4.2±3.2%, in agreement with the Standard Model prediction at next-to-leading order. A differential measurement in three tt¯ mass bins is also presented.

    Original languageEnglish
    Pages (from-to)52-71
    Number of pages20
    JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
    Volume756
    DOIs
    Publication statusPublished - 2016 May 10

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    pair production
    asymmetry
    quarks
    collisions
    angular distribution
    topology
    decay
    predictions

    ASJC Scopus subject areas

    • Nuclear and High Energy Physics

    Cite this

    @article{7cf1c3635ba04453af82e0657f94bf6b,
    title = "Measurement of the charge asymmetry in highly boosted top-quark pair production in √s=8 TeV pp collision data collected by the ATLAS experiment",
    abstract = "In the pp→tt¯ process the angular distributions of top and anti-top quarks are expected to present a subtle difference, which could be enhanced by processes not included in the Standard Model. This Letter presents a measurement of the charge asymmetry in events where the top-quark pair is produced with a large invariant mass. The analysis is performed on 20.3 fb−1 of pp collision data at s=8TeV collected by the ATLAS experiment at the LHC, using reconstruction techniques specifically designed for the decay topology of highly boosted top quarks. The charge asymmetry in a fiducial region with large invariant mass of the top-quark pair (mtt¯>0.75 TeV) and an absolute rapidity difference of the top and anti-top quark candidates within −2<|yt|−|yt¯|<2 is measured to be 4.2±3.2{\%}, in agreement with the Standard Model prediction at next-to-leading order. A differential measurement in three tt¯ mass bins is also presented.",
    author = "{ATLAS Collaboration} and G. Aad and B. Abbott and J. Abdallah and O. Abdinov and B. Abeloos 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 J. Alison and Alkire, {S. P.} and Allbrooke, {B. M.M.} and Allen, {B. W.} and Allport, {P. P.} and A. Aloisio and A. Alonso and F. Alonso and Takashi Mitani and Masahiro Morinaga and Kohei Yorita",
    year = "2016",
    month = "5",
    day = "10",
    doi = "10.1016/j.physletb.2016.02.055",
    language = "English",
    volume = "756",
    pages = "52--71",
    journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",
    issn = "0370-2693",
    publisher = "Elsevier",

    }

    TY - JOUR

    T1 - Measurement of the charge asymmetry in highly boosted top-quark pair production in √s=8 TeV pp collision data collected by the ATLAS experiment

    AU - ATLAS Collaboration

    AU - Aad, G.

    AU - Abbott, B.

    AU - Abdallah, J.

    AU - Abdinov, O.

    AU - Abeloos, B.

    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 - Alison, J.

    AU - Alkire, S. P.

    AU - Allbrooke, B. M.M.

    AU - Allen, B. W.

    AU - Allport, P. P.

    AU - Aloisio, A.

    AU - Alonso, A.

    AU - Alonso, F.

    AU - Mitani, Takashi

    AU - Morinaga, Masahiro

    AU - Yorita, Kohei

    PY - 2016/5/10

    Y1 - 2016/5/10

    N2 - In the pp→tt¯ process the angular distributions of top and anti-top quarks are expected to present a subtle difference, which could be enhanced by processes not included in the Standard Model. This Letter presents a measurement of the charge asymmetry in events where the top-quark pair is produced with a large invariant mass. The analysis is performed on 20.3 fb−1 of pp collision data at s=8TeV collected by the ATLAS experiment at the LHC, using reconstruction techniques specifically designed for the decay topology of highly boosted top quarks. The charge asymmetry in a fiducial region with large invariant mass of the top-quark pair (mtt¯>0.75 TeV) and an absolute rapidity difference of the top and anti-top quark candidates within −2<|yt|−|yt¯|<2 is measured to be 4.2±3.2%, in agreement with the Standard Model prediction at next-to-leading order. A differential measurement in three tt¯ mass bins is also presented.

    AB - In the pp→tt¯ process the angular distributions of top and anti-top quarks are expected to present a subtle difference, which could be enhanced by processes not included in the Standard Model. This Letter presents a measurement of the charge asymmetry in events where the top-quark pair is produced with a large invariant mass. The analysis is performed on 20.3 fb−1 of pp collision data at s=8TeV collected by the ATLAS experiment at the LHC, using reconstruction techniques specifically designed for the decay topology of highly boosted top quarks. The charge asymmetry in a fiducial region with large invariant mass of the top-quark pair (mtt¯>0.75 TeV) and an absolute rapidity difference of the top and anti-top quark candidates within −2<|yt|−|yt¯|<2 is measured to be 4.2±3.2%, in agreement with the Standard Model prediction at next-to-leading order. A differential measurement in three tt¯ mass bins is also presented.

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    U2 - 10.1016/j.physletb.2016.02.055

    DO - 10.1016/j.physletb.2016.02.055

    M3 - Article

    VL - 756

    SP - 52

    EP - 71

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

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

    SN - 0370-2693

    ER -