Search for single top-quark production via flavour-changing neutral currents at 8 TeV with the ATLAS detector
Springer, 2016
Online
academicJournal
- 30
Zugriff:
A search for single top-quark production via flavour-changing neutral current processes from gluon plus up- or charm-quark initial states in proton–proton collisions at the LHC is presented. Data collected with the ATLAS detector in 2012 at a centre-of-mass energy of 8 TeV and corresponding to an integrated luminosity of 20.3 fb $$^{-1}$$ - 1 are used. Candidate events for a top quark decaying into a lepton, a neutrino and a jet are selected and classified into signal- and background-like candidates using a neural network. No signal is observed and an upper limit on the production cross-section multiplied by the $$t \rightarrow Wb$$ t → W b branching fraction is set. The observed 95 % CL limit is $$\sigma _{qg \rightarrow t} {\,\times \,} \mathcal {B}(t \rightarrow Wb)< {3.4}\,\mathrm{pb}$$ σ q g → t × B ( t → W b ) < 3.4 pb and the expected 95 % CL limit is $$\sigma _{qg \rightarrow t} \times \mathcal {B}(t \rightarrow Wb)< {2.9}\,\mathrm{pb}$$ σ q g → t × B ( t → W b ) < 2.9 pb . The observed limit can be interpreted as upper limits on the coupling constants of the flavour-changing neutral current interactions divided by the scale of new physics $$\kappa _{ugt}/\Lambda < 5.8 \times 10^{-3}\, \mathrm{TeV}^{-1}$$ κ u g t / Λ < 5.8 × 10 - 3 TeV - 1 and $$\kappa _{cgt}/\Lambda < 13 \times 10^{-3}\, \mathrm{TeV}$$ κ c g t / Λ < 13 × 10 - 3 TeV and on the branching fractions $$\mathcal {B}(t \rightarrow ug) < {4.0 \times 10^{-5}}$$ B ( t → u g ) < 4.0 × 10 - 5 and $$\mathcal {B}(t \rightarrow cg) < {20 \times 10^{-5}}$$ B ( t → c g ) < 20 × 10 - 5 .
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Search for single top-quark production via flavour-changing neutral currents at 8 TeV with the ATLAS detector
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Autor/in / Beteiligte Person: | Aad, G. ; Abbott, B. ; Abdallah, J. ; Abdinov, O. ; Aben, R. ; Abolins, M. ; AbouZeid, O. ; Abramowicz, H. ; Abreu, H. ; Abreu, R. ; Abulaiti, Y. ; Acharya, B. ; Adamczyk, L. ; Adams, D. ; Adelman, J. ; Adomeit, S. ; Adye, T. ; Affolder, A. ; Agatonovic-Jovin, T. ; Agricola, J. ; Aguilar-Saavedra, J. ; Ahlen, S. ; Ahmadov, F. ; Aielli, G. ; Akerstedt, H. ; Åkesson, T. |
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Veröffentlichung: | Springer, 2016 |
Medientyp: | academicJournal |
Umfang: | 30 |
DOI: | 10.1140/epjc/s10052-016-3876-4 |
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