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 - Aleksa, M.
AU - Aleksandrov, I. N.
AU - Alexa, C.
AU - Alexopoulos, T.
AU - Belfkir, Mohamed
AU - Nasri, S.
N1 - Publisher Copyright:
© 2023 The Author(s)
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 - http://www.scopus.com/inward/record.url?scp=85164136591&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85164136591&partnerID=8YFLogxK
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 -