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Search for flavour-changing neutral current top-quark decays t → qZ in proton-proton collisions at √s=13 TeV with the ATLAS detector. / The ATLAS collaboration.
In: Journal of High Energy Physics, Vol. 2018, No. 7, 176, 01.07.2018.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Search for flavour-changing neutral current top-quark decays t → qZ in proton-proton collisions at √s=13 TeV with the ATLAS detector
AU - The ATLAS collaboration
AU - Aaboud, M.
AU - Aad, G.
AU - Abbott, B.
AU - Abdinov, O.
AU - Abeloos, B.
AU - Abidi, S. H.
AU - AbouZeid, O. S.
AU - Abraham, N. L.
AU - Abramowicz, H.
AU - Abreu, H.
AU - Abulaiti, Y.
AU - Acharya, B. S.
AU - Adachi, S.
AU - Adamczyk, L.
AU - Adelman, J.
AU - Adersberger, M.
AU - Adye, T.
AU - Affolder, A. A.
AU - Afik, Y.
AU - Agheorghiesei, C.
AU - Aguilar-Saavedra, J. A.
AU - Ahmadov, F.
AU - Aielli, G.
AU - Akatsuka, S.
AU - Akerstedt, H.
AU - Åkesson, T. P.A.
AU - Akilli, E.
AU - Akimov, A. V.
AU - Alberghi, G. L.
AU - Albert, J.
AU - Albicocco, P.
AU - Alconada Verzini, M. J.
AU - Alderweireldt, S.
AU - Aleksa, M.
AU - Aleksandrov, I. N.
AU - Alexa, C.
AU - Alexander, G.
AU - Alexopoulos, T.
AU - Alhroob, M.
AU - Ali, B.
AU - Aliev, M.
AU - Alimonti, G.
AU - Anisenkov, A. V.
AU - Baldin, E. M.
AU - Bobrovnikov, V. S.
AU - Buzykaev, A. R.
AU - Kharlamov, A. G.
AU - Maslennikov, A. L.
AU - Talyshev, A. A.
AU - Tikhonov, Yu A.
N1 - Publisher Copyright: © 2018, The Author(s).
PY - 2018/7/1
Y1 - 2018/7/1
N2 - A search for flavour-changing neutral-current processes in top-quark decays is presented. Data collected with the ATLAS detector from proton-proton collisions at the Large Hadron Collider at a centre-of-mass energy of s=13 TeV, corresponding to an integrated luminosity of 36.1 fb−1, are analysed. The search is performed using top-quark pair events, with one top quark decaying through the t → qZ (q = u, c) flavour-changing neutral-current channel, and the other through the dominant Standard Model mode t → bW. Only Z boson decays into charged leptons and leptonic W boson decays are considered as signal. Consequently, the final-state topology is characterized by the presence of three isolated charged leptons (electrons or muons), at least two jets, one of the jets originating from a b-quark, and missing transverse momentum from the undetected neutrino. The data are consistent with Standard Model background contributions, and at 95% confidence level the search sets observed (expected) upper limits of 1.7 × 10−4 (2.4 × 10−4) on the t → uZ branching ratio and 2.4 × 10−4 (3.2 × 10−4) on the t → cZ branching ratio, constituting the most stringent limits to date.
AB - A search for flavour-changing neutral-current processes in top-quark decays is presented. Data collected with the ATLAS detector from proton-proton collisions at the Large Hadron Collider at a centre-of-mass energy of s=13 TeV, corresponding to an integrated luminosity of 36.1 fb−1, are analysed. The search is performed using top-quark pair events, with one top quark decaying through the t → qZ (q = u, c) flavour-changing neutral-current channel, and the other through the dominant Standard Model mode t → bW. Only Z boson decays into charged leptons and leptonic W boson decays are considered as signal. Consequently, the final-state topology is characterized by the presence of three isolated charged leptons (electrons or muons), at least two jets, one of the jets originating from a b-quark, and missing transverse momentum from the undetected neutrino. The data are consistent with Standard Model background contributions, and at 95% confidence level the search sets observed (expected) upper limits of 1.7 × 10−4 (2.4 × 10−4) on the t → uZ branching ratio and 2.4 × 10−4 (3.2 × 10−4) on the t → cZ branching ratio, constituting the most stringent limits to date.
KW - Hadron-Hadron scattering (experiments)
KW - PARTON DISTRIBUTIONS
KW - PAIR-PRODUCTION
KW - MODELS
KW - PLUS PLUS
KW - PHYSICS
KW - CROSS-SECTION
UR - http://www.scopus.com/inward/record.url?scp=85051260203&partnerID=8YFLogxK
U2 - 10.1007/JHEP07(2018)176
DO - 10.1007/JHEP07(2018)176
M3 - Article
AN - SCOPUS:85051260203
VL - 2018
JO - Journal of High Energy Physics
JF - Journal of High Energy Physics
SN - 1029-8479
IS - 7
M1 - 176
ER -
ID: 16133890