Search for Anomalous Wtb Couplings and Flavour-Changing Neutral Currents in t-Channel Single Top Quark Production in Pp Collisions at √s = 7 and 8 TeV
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Khachatryan2017_Article_SearchForAnomalousWTbCouplings.pdf
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Author(s)
CMS Collaboration
Abercrombie, Daniel Robert
Allen, Brandon Leigh
Apyan, Aram
Barbieri, Richard Alexander
Baty, Austin Alan
Bi, Ran
Bierwagen, Katharina
Brandt, Stephanie Akemi
Busza, Wit
Date Issued
February 2017
Journal
Journal of High Energy Physics
Publisher
Springer Nature
Citation
Khachatryan, V. et al. “Search for Anomalous Wtb Couplings and Flavour-Changing Neutral Currents in t-Channel Single Top Quark Production in Pp Collisions at √s = 7 and 8 TeV.” Journal of High Energy Physics 2017, 2 (February 2017): 28 © 2017 The Author(s)
Version
Final published version
Abstract
Single top quark events produced in the t channel are used to set limits on anomalous Wtb couplings and to search for top quark flavour-changing neutral current (FCNC) interactions. The data taken with the CMS detector at the LHC in proton-proton collisions at √s = 7 and 8 TeV correspond to integrated luminosities of 5.0 and 19.7 fb⁻¹, respectively. The analysis is performed using events with one muon and two or three jets. A Bayesian neural network technique is used to discriminate between the signal and backgrounds, which are observed to be consistent with the standard model prediction. The 95% confidence level (CL) exclusion limits on anomalous right-handed vector, and left- and right-handed tensor Wtb couplings are measured to be |fVR| < 0.16, |fTL| < 0.057, and − 0.049 < fTR< 0.048, respectively. For the FCNC couplings κtugand κtcg, the 95% CL upper limits on coupling strengths are |κtug|/Λ < 4.1 × 10⁻³TeV⁻¹and |κtcg|/Λ < 1.8 × 10⁻²TeV⁻¹, where Λ is the scale for new physics, and correspond to upper limits on the branching fractions of 2.0 × 10⁻⁵ and 4.1 × 10⁻⁴ for the decays t → ug and t → cg, respectively. Keywords: Flavour Changing Neutral Currents; Hadron-Hadron scattering (experiments); Top physics
MIT Department
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
Massachusetts Institute of Technology. Department of Physics
Massachusetts Institute of Technology. Laboratory for Nuclear Science
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Creative Commons Attribution 4.0 International License
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DOI of Published Version
https://doi.org/10.1007/JHEP02(2017)028
