Evidence for the Associated Production of a Single Top Quark and a Photon in Proton-Proton Collisions at s =13 TeV

CMS Collaboration

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

The first evidence of events consistent with the production of a single top quark in association with a photon is reported. The analysis is based on proton-proton collisions at s=13 TeV and recorded by the CMS experiment in 2016, corresponding to an integrated luminosity of 35.9 fb-1. Events are selected by requiring the presence of a muon (μ), a photon (γ), an imbalance in transverse momentum from an undetected neutrino (ν), and at least two jets (j) of which exactly one is identified as associated with the hadronization of a b quark. A multivariate discriminant based on topological and kinematic event properties is employed to separate signal from background processes. An excess above the background-only hypothesis is observed, with a significance of 4.4 standard deviations. A fiducial cross section is measured for isolated photons with transverse momentum greater than 25 GeV in the central region of the detector. The measured product of the cross section and branching fraction is σ(pp→tγj)B(t→μνb)=115±17(stat)±30(syst) fb, which is consistent with the standard model prediction.

Original languageEnglish
Article number221802
JournalPhysical Review Letters
Volume121
Issue number22
DOIs
Publication statusPublished - 29 Nov 2018

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quarks
transverse momentum
collisions
protons
photons
cross sections
muons
standard deviation
kinematics
neutrinos
luminosity
detectors
products
predictions

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Evidence for the Associated Production of a Single Top Quark and a Photon in Proton-Proton Collisions at s =13 TeV. / CMS Collaboration.

In: Physical Review Letters, Vol. 121, No. 22, 221802, 29.11.2018.

Research output: Contribution to journalArticle

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abstract = "The first evidence of events consistent with the production of a single top quark in association with a photon is reported. The analysis is based on proton-proton collisions at s=13 TeV and recorded by the CMS experiment in 2016, corresponding to an integrated luminosity of 35.9 fb-1. Events are selected by requiring the presence of a muon (μ), a photon (γ), an imbalance in transverse momentum from an undetected neutrino (ν), and at least two jets (j) of which exactly one is identified as associated with the hadronization of a b quark. A multivariate discriminant based on topological and kinematic event properties is employed to separate signal from background processes. An excess above the background-only hypothesis is observed, with a significance of 4.4 standard deviations. A fiducial cross section is measured for isolated photons with transverse momentum greater than 25 GeV in the central region of the detector. The measured product of the cross section and branching fraction is σ(pp→tγj)B(t→μνb)=115±17(stat)±30(syst) fb, which is consistent with the standard model prediction.",
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N2 - The first evidence of events consistent with the production of a single top quark in association with a photon is reported. The analysis is based on proton-proton collisions at s=13 TeV and recorded by the CMS experiment in 2016, corresponding to an integrated luminosity of 35.9 fb-1. Events are selected by requiring the presence of a muon (μ), a photon (γ), an imbalance in transverse momentum from an undetected neutrino (ν), and at least two jets (j) of which exactly one is identified as associated with the hadronization of a b quark. A multivariate discriminant based on topological and kinematic event properties is employed to separate signal from background processes. An excess above the background-only hypothesis is observed, with a significance of 4.4 standard deviations. A fiducial cross section is measured for isolated photons with transverse momentum greater than 25 GeV in the central region of the detector. The measured product of the cross section and branching fraction is σ(pp→tγj)B(t→μνb)=115±17(stat)±30(syst) fb, which is consistent with the standard model prediction.

AB - The first evidence of events consistent with the production of a single top quark in association with a photon is reported. The analysis is based on proton-proton collisions at s=13 TeV and recorded by the CMS experiment in 2016, corresponding to an integrated luminosity of 35.9 fb-1. Events are selected by requiring the presence of a muon (μ), a photon (γ), an imbalance in transverse momentum from an undetected neutrino (ν), and at least two jets (j) of which exactly one is identified as associated with the hadronization of a b quark. A multivariate discriminant based on topological and kinematic event properties is employed to separate signal from background processes. An excess above the background-only hypothesis is observed, with a significance of 4.4 standard deviations. A fiducial cross section is measured for isolated photons with transverse momentum greater than 25 GeV in the central region of the detector. The measured product of the cross section and branching fraction is σ(pp→tγj)B(t→μνb)=115±17(stat)±30(syst) fb, which is consistent with the standard model prediction.

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