Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
Measurement of the polarisation of single top quarks and antiquarks produced in the t-channel at √s = 13 TeV and bounds on the tWb dipole operator from the ATLAS experiment. / The ATLAS collaboration.
в: Journal of High Energy Physics, Том 2022, № 11, 40, 11.2022.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Measurement of the polarisation of single top quarks and antiquarks produced in the t-channel at √s = 13 TeV and bounds on the tWb dipole operator from the ATLAS experiment
AU - The ATLAS collaboration
AU - Aad, G.
AU - Abbott, B.
AU - Abbott, D. C.
AU - Abed Abud, A.
AU - Abeling, K.
AU - Abhayasinghe, D. K.
AU - Abidi, S. H.
AU - Abramowicz, H.
AU - Abreu, H.
AU - Abulaiti, Y.
AU - Abusleme Hoffman, A. C.
AU - Acharya, B. S.
AU - Achkar, B.
AU - Adam, L.
AU - Adam Bourdarios, C.
AU - Adamczyk, L.
AU - Adamek, L.
AU - Addepalli, S. V.
AU - Adelman, J.
AU - Adiguzel, A.
AU - Adorni, S.
AU - Adye, T.
AU - Affolder, A. A.
AU - Afik, Y.
AU - Agapopoulou, C.
AU - Agaras, M. N.
AU - Agarwala, J.
AU - Aggarwal, A.
AU - Agheorghiesei, C.
AU - Aguilar-Saavedra, J. A.
AU - Ahmad, A.
AU - Ahmadov, F.
AU - Ahmed, W. S.
AU - Anisenkov, A. V.
AU - Baldin, E. M.
AU - Beloborodov, K.
AU - Bobrovnikov, V. S.
AU - Buzykaev, A. R.
AU - Kazanin, V. F.
AU - Kharlamov, A. G.
AU - Kharlamova, T.
AU - Maslennikov, A. L.
AU - Maximov, D. A.
AU - Peleganchuk, S. V.
AU - Podberezko, P.
AU - Rezanova, O. L.
AU - Soukharev, A. M.
AU - Talyshev, A. A.
AU - Tikhonov, Yu A.
AU - Zhulanov, V.
N1 - Publisher Copyright: © 2022, The Author(s).
PY - 2022/11
Y1 - 2022/11
N2 - A simultaneous measurement of the three components of the top-quark and top-antiquark polarisation vectors in t-channel single-top-quark production is presented. This analysis is based on data from proton–proton collisions at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 139 fb−1, collected with the ATLAS detector at the LHC. Selected events contain exactly one isolated electron or muon, large missing transverse momentum and exactly two jets, one being b-tagged. Stringent selection requirements are applied to discriminate t-channel single-top-quark events from the background contributions. The top-quark and top-antiquark polarisation vectors are measured from the distributions of the direction cosines of the charged-lepton momentum in the top-quark rest frame. The three components of the polarisation vector for the selected top-quark event sample are Px′ = 0.01 ± 0.18, Py′ = −0.029 ± 0.027, Pz′ = 0.91 ± 0.10 and for the top-antiquark event sample they are Px′ = −0.02 ± 0.20, Py′ = −0.007 ± 0.051, Pz′ = 0.79 ± 0.16. Normalised differential cross-sections corrected to a fiducial region at the stable-particle level are presented as a function of the charged-lepton angles for top-quark and top-antiquark events inclusively and separately. These measurements are in agreement with Standard Model predictions. The angular differential cross-sections are used to derive bounds on the complex Wilson coefficient of the dimension-six OtW operator in the framework of an effective field theory. The obtained bounds are CtW ∈ [−0.9, 1.4] and CitW ∈ [−0.8, 0.2], both at 95% confidence level.
AB - A simultaneous measurement of the three components of the top-quark and top-antiquark polarisation vectors in t-channel single-top-quark production is presented. This analysis is based on data from proton–proton collisions at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 139 fb−1, collected with the ATLAS detector at the LHC. Selected events contain exactly one isolated electron or muon, large missing transverse momentum and exactly two jets, one being b-tagged. Stringent selection requirements are applied to discriminate t-channel single-top-quark events from the background contributions. The top-quark and top-antiquark polarisation vectors are measured from the distributions of the direction cosines of the charged-lepton momentum in the top-quark rest frame. The three components of the polarisation vector for the selected top-quark event sample are Px′ = 0.01 ± 0.18, Py′ = −0.029 ± 0.027, Pz′ = 0.91 ± 0.10 and for the top-antiquark event sample they are Px′ = −0.02 ± 0.20, Py′ = −0.007 ± 0.051, Pz′ = 0.79 ± 0.16. Normalised differential cross-sections corrected to a fiducial region at the stable-particle level are presented as a function of the charged-lepton angles for top-quark and top-antiquark events inclusively and separately. These measurements are in agreement with Standard Model predictions. The angular differential cross-sections are used to derive bounds on the complex Wilson coefficient of the dimension-six OtW operator in the framework of an effective field theory. The obtained bounds are CtW ∈ [−0.9, 1.4] and CitW ∈ [−0.8, 0.2], both at 95% confidence level.
KW - Hadron-Hadron Scattering
KW - Top Physics
UR - http://www.scopus.com/inward/record.url?scp=85144205100&partnerID=8YFLogxK
U2 - 10.1007/JHEP11(2022)040
DO - 10.1007/JHEP11(2022)040
M3 - Article
AN - SCOPUS:85144205100
VL - 2022
JO - Journal of High Energy Physics
JF - Journal of High Energy Physics
SN - 1029-8479
IS - 11
M1 - 40
ER -
ID: 41156265