Search for pair-production of vector-like quarks in pp collision events at s=13 TeV with at least one leptonically decaying Z boson and a third-generation quark with the ATLAS detector

The ATLAS collaboration

doi:10.1016/j.physletb.2023.138019

Search for pair-production of vector-like quarks in pp collision events at s=13 TeV with at least one leptonically decaying Z boson and a third-generation quark with the ATLAS detector

The ATLAS collaboration

Aix-Marseille Université
University of Oklahoma
University of Göttingen
TU Dortmund University
United States Department of Energy
Mohammed V University in Rabat
Tel Aviv University
Technion-Israel Institute of Technology
New York University
National Institute for Nuclear Physics
Abdus Salam International Centre for Theoretical Physics
King's College London
Université Savoie Mont Blanc
AGH University of Krakow
Brandeis University
University of Manchester
Northern Illinois University
Istanbul University
Rutherford Appleton Laboratory
University of California at Santa Cruz
CERN
Institute for High Energy Physics
University of Pavia
Johannes Gutenberg University Mainz
Alexandru Ioan Cuza University of Iaşi
Azerbaijan National Academy of Sciences
McGill University
Royal Holloway University of London
University of Science and Technology of China
University of Rome Tor Vergata
University of Valencia
University of Hassan II Casablanca
Weizmann Institute of Science
Lund University
Waseda University
University of Bonn
Columbia University
University of Victoria BC
Université Grenoble Alpes
University of Edinburgh

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

44 Scopus citations

Abstract

A search for the pair-production of vector-like quarks optimized for decays into a Z boson and a third-generation Standard Model quark is presented, using the full Run 2 dataset corresponding to 139fb⁻¹ of pp collisions at s=13TeV, collected in 2015–2018 with the ATLAS detector at the Large Hadron Collider. The targeted final state is characterized by the presence of a Z boson with high transverse momentum, reconstructed from a pair of same-flavour leptons with opposite-sign charges, as well as by the presence of b-tagged jets and high-transverse-momentum large-radius jets reconstructed from calibrated smaller-radius jets. Events with exactly two or at least three leptons are used, which are further categorized by the presence of boosted W, Z, and Higgs bosons and top quarks. The categorization is performed using a neural-network-based boosted object tagger to enhance the sensitivity to signal relative to the background. No significant excess above the background expectation is observed and exclusion limits at 95% confidence level are set on the masses of the vector-like partners T and B of the top and bottom quarks, respectively. The limits depend on the branching ratio configurations and, in the case of 100% branching ratio for T→Zt and 100% branching ratio for B→Zb, this search sets the most stringent limits to date, allowing m_T>1.60TeV and m_B>1.42TeV, respectively.

Original language	English
Article number	138019
Journal	Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume	843
DOIs	https://doi.org/10.1016/j.physletb.2023.138019
State	Published - Aug 10 2023

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10.1016/j.physletb.2023.138019

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@article{5a7a93bb72e8457a826c31968b0c5217,

title = "Search for pair-production of vector-like quarks in pp collision events at s=13 TeV with at least one leptonically decaying Z boson and a third-generation quark with the ATLAS detector",

abstract = "A search for the pair-production of vector-like quarks optimized for decays into a Z boson and a third-generation Standard Model quark is presented, using the full Run 2 dataset corresponding to 139fb−1 of pp collisions at s=13TeV, collected in 2015{\textendash}2018 with the ATLAS detector at the Large Hadron Collider. The targeted final state is characterized by the presence of a Z boson with high transverse momentum, reconstructed from a pair of same-flavour leptons with opposite-sign charges, as well as by the presence of b-tagged jets and high-transverse-momentum large-radius jets reconstructed from calibrated smaller-radius jets. Events with exactly two or at least three leptons are used, which are further categorized by the presence of boosted W, Z, and Higgs bosons and top quarks. The categorization is performed using a neural-network-based boosted object tagger to enhance the sensitivity to signal relative to the background. No significant excess above the background expectation is observed and exclusion limits at 95\% confidence level are set on the masses of the vector-like partners T and B of the top and bottom quarks, respectively. The limits depend on the branching ratio configurations and, in the case of 100\% branching ratio for T→Zt and 100\% branching ratio for B→Zb, this search sets the most stringent limits to date, allowing mT>1.60TeV and mB>1.42TeV, respectively.",

author = "\{The ATLAS collaboration\} and G. Aad and B. Abbott and K. Abeling and Abicht, \{N. J.\} and Abidi, \{S. H.\} and A. Aboulhorma and H. Abramowicz and H. Abreu and Y. Abulaiti and Acharya, \{B. S.\} and \{Adam Bourdarios\}, C. and L. Adamczyk and Addepalli, \{S. V.\} and Addison, \{M. J.\} and J. Adelman and A. Adiguzel and T. Adye and Affolder, \{A. A.\} and Y. Afik and Agaras, \{M. N.\} and J. Agarwala and A. Aggarwal and C. Agheorghiesei and A. Ahmad and F. Ahmadov and Ahmed, \{W. S.\} and S. Ahuja and X. Ai and G. Aielli and A. Aikot and \{Ait Tamlihat\}, M. and B. Aitbenchikh and I. Aizenberg and M. Akbiyik and {\AA}kesson, \{T. P.A.\} and Akimov, \{A. V.\} and D. Akiyama and Akolkar, \{N. N.\} and \{Al Khoury\}, K. and Alberghi, \{G. L.\} and J. Albert and P. Albicocco and Albouy, \{G. L.\} and S. Alderweireldt and H. Arnold and V. Dao and J. Hobbs and J. Jia and Piacquadio, \{Nicola Giacinto\} and D. Tsybychev",

note = "Publisher Copyright: {\textcopyright} 2023 The Author(s)",

year = "2023",

month = aug,

day = "10",

doi = "10.1016/j.physletb.2023.138019",

language = "English",

volume = "843",

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

issn = "0370-2693",

}

Search for pair-production of vector-like quarks in pp collision events at s=13 TeV with at least one leptonically decaying Z boson and a third-generation quark with the ATLAS detector. / The ATLAS collaboration.
In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, Vol. 843, 138019, 10.08.2023.

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

TY - JOUR

T1 - Search for pair-production of vector-like quarks in pp collision events at s=13 TeV with at least one leptonically decaying Z boson and a third-generation quark with the ATLAS detector

AU - The ATLAS collaboration

AU - Aad, G.

AU - Abbott, B.

AU - Abeling, K.

AU - Abicht, N. J.

AU - Abidi, S. H.

AU - Aboulhorma, A.

AU - Abramowicz, H.

AU - Abreu, H.

AU - Abulaiti, Y.

AU - Acharya, B. S.

AU - Adam Bourdarios, C.

AU - Adamczyk, L.

AU - Addepalli, S. V.

AU - Addison, M. J.

AU - Adelman, J.

AU - Adiguzel, A.

AU - Adye, T.

AU - Affolder, A. A.

AU - Afik, Y.

AU - Agaras, M. N.

AU - Agarwala, J.

AU - Aggarwal, A.

AU - Agheorghiesei, C.

AU - Ahmad, A.

AU - Ahmadov, F.

AU - Ahmed, W. S.

AU - Ahuja, S.

AU - Ai, X.

AU - Aielli, G.

AU - Aikot, A.

AU - Ait Tamlihat, M.

AU - Aitbenchikh, B.

AU - Aizenberg, I.

AU - Akbiyik, M.

AU - Åkesson, T. P.A.

AU - Akimov, A. V.

AU - Akiyama, D.

AU - Akolkar, N. N.

AU - Al Khoury, K.

AU - Alberghi, G. L.

AU - Albert, J.

AU - Albicocco, P.

AU - Albouy, G. L.

AU - Alderweireldt, S.

AU - Arnold, H.

AU - Dao, V.

AU - Hobbs, J.

AU - Jia, J.

AU - Piacquadio, Nicola Giacinto

AU - Tsybychev, D.

PY - 2023/8/10

Y1 - 2023/8/10

N2 - A search for the pair-production of vector-like quarks optimized for decays into a Z boson and a third-generation Standard Model quark is presented, using the full Run 2 dataset corresponding to 139fb−1 of pp collisions at s=13TeV, collected in 2015–2018 with the ATLAS detector at the Large Hadron Collider. The targeted final state is characterized by the presence of a Z boson with high transverse momentum, reconstructed from a pair of same-flavour leptons with opposite-sign charges, as well as by the presence of b-tagged jets and high-transverse-momentum large-radius jets reconstructed from calibrated smaller-radius jets. Events with exactly two or at least three leptons are used, which are further categorized by the presence of boosted W, Z, and Higgs bosons and top quarks. The categorization is performed using a neural-network-based boosted object tagger to enhance the sensitivity to signal relative to the background. No significant excess above the background expectation is observed and exclusion limits at 95% confidence level are set on the masses of the vector-like partners T and B of the top and bottom quarks, respectively. The limits depend on the branching ratio configurations and, in the case of 100% branching ratio for T→Zt and 100% branching ratio for B→Zb, this search sets the most stringent limits to date, allowing mT>1.60TeV and mB>1.42TeV, respectively.

AB - A search for the pair-production of vector-like quarks optimized for decays into a Z boson and a third-generation Standard Model quark is presented, using the full Run 2 dataset corresponding to 139fb−1 of pp collisions at s=13TeV, collected in 2015–2018 with the ATLAS detector at the Large Hadron Collider. The targeted final state is characterized by the presence of a Z boson with high transverse momentum, reconstructed from a pair of same-flavour leptons with opposite-sign charges, as well as by the presence of b-tagged jets and high-transverse-momentum large-radius jets reconstructed from calibrated smaller-radius jets. Events with exactly two or at least three leptons are used, which are further categorized by the presence of boosted W, Z, and Higgs bosons and top quarks. The categorization is performed using a neural-network-based boosted object tagger to enhance the sensitivity to signal relative to the background. No significant excess above the background expectation is observed and exclusion limits at 95% confidence level are set on the masses of the vector-like partners T and B of the top and bottom quarks, respectively. The limits depend on the branching ratio configurations and, in the case of 100% branching ratio for T→Zt and 100% branching ratio for B→Zb, this search sets the most stringent limits to date, allowing mT>1.60TeV and mB>1.42TeV, respectively.

UR - https://www.scopus.com/pages/publications/85164136591

U2 - 10.1016/j.physletb.2023.138019

DO - 10.1016/j.physletb.2023.138019

M3 - Article

AN - SCOPUS:85164136591

SN - 0370-2693

VL - 843

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

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

M1 - 138019

ER -

Search for pair-production of vector-like quarks in pp collision events at s=13 TeV with at least one leptonically decaying Z boson and a third-generation quark with the ATLAS detector

Abstract

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