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
Aad, G. ; Åkesson, T.P.A. LU
; Corrigan, E.E.
LU
; Doglioni, C.
LU
; Geisen, J.
LU
; Hansen, E.
LU
; Hedberg, V.
LU
; Herde, Hannah
LU
; Jarlskog, G.
LU
and Konya, B.
LU
, et al.
(2022)
In Journal of High Energy Physics
2022(11).
- Abstract
- 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... (More)
- 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. [Figure not available: see fulltext.]. © 2022, The Author(s). (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/dcd4af56-8b98-4b75-8765-8435addb7a6b
- author
- Aad, G.
; Åkesson, T.P.A.
LU
; Corrigan, E.E.
LU
; Doglioni, C.
LU
; Geisen, J.
LU
; Hansen, E.
LU
; Hedberg, V.
LU
; Herde, Hannah
LU
; Jarlskog, G.
LU
and Konya, B.
LU
, et al. (More)
- Aad, G.
; Åkesson, T.P.A.
LU
; Corrigan, E.E.
LU
; Doglioni, C.
LU
; Geisen, J.
LU
; Hansen, E.
LU
; Hedberg, V.
LU
; Herde, Hannah
LU
; Jarlskog, G.
LU
; Konya, B.
LU
; Lytken, E.
LU
; Mankinen, K.H.
LU
; Marcon, C.
LU
; Mjörnmark, J.U.
LU
; Mullier, G.A.
LU
; Poettgen, R.
LU
; Skorda, E.
LU
; Smirnova, O.
LU
and Zwalinski, L.
(Less)
- author collaboration
- organization
- publishing date
- 2022
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Hadron-Hadron Scattering, Top Physics
- in
- Journal of High Energy Physics
- volume
- 2022
- issue
- 11
- article number
- 40
- publisher
- Springer
- external identifiers
-
- scopus:85144205100
- ISSN
- 1029-8479
- DOI
- 10.1007/JHEP11(2022)040
- language
- English
- LU publication?
- yes
- id
- dcd4af56-8b98-4b75-8765-8435addb7a6b
- date added to LUP
- 2023-01-16 09:30:53
- date last changed
- 2023-04-06 06:53:01
@article{dcd4af56-8b98-4b75-8765-8435addb7a6b,
abstract = {{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. [Figure not available: see fulltext.]. © 2022, The Author(s).}},
author = {{Aad, G. and Åkesson, T.P.A. and Corrigan, E.E. and Doglioni, C. and Geisen, J. and Hansen, E. and Hedberg, V. and Herde, Hannah and Jarlskog, G. and Konya, B. and Lytken, E. and Mankinen, K.H. and Marcon, C. and Mjörnmark, J.U. and Mullier, G.A. and Poettgen, R. and Skorda, E. and Smirnova, O. and Zwalinski, L.}},
issn = {{1029-8479}},
keywords = {{Hadron-Hadron Scattering; Top Physics}},
language = {{eng}},
number = {{11}},
publisher = {{Springer}},
series = {{Journal of High Energy Physics}},
title = {{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}},
url = {{http://dx.doi.org/10.1007/JHEP11(2022)040}},
doi = {{10.1007/JHEP11(2022)040}},
volume = {{2022}},
year = {{2022}},
}