KIT | KIT-Bibliothek | Impressum | Datenschutz

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

CMS Collaboration; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Dragicevic, M.; Erö, J.; Escalante Del Valle, A.; Flechl, M.; Frühwirth, R.; Ghete, V. M.; Hrubec, J.; Jeitler, M.; Krammer, N.; Krätschmer, I.; Liko, D.; Madlener, T.; Mikulec, I.; ... mehr

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.

Open Access Logo


Verlagsausgabe §
DOI: 10.5445/IR/1000089152
Veröffentlicht am 07.01.2019
Originalveröffentlichung
DOI: 10.1103/PhysRevLett.121.221802
Scopus
Zitationen: 1
Zugehörige Institution(en) am KIT Institut für Prozessdatenverarbeitung und Elektronik (IPE)
Institut für Experimentelle Teilchenphysik (ETP)
Publikationstyp Zeitschriftenaufsatz
Jahr 2018
Sprache Englisch
Identifikator ISSN: 0031-9007, 1079-7114
urn:nbn:de:swb:90-891529
KITopen-ID: 1000089152
Erschienen in Physical review letters
Band 121
Heft 22
Seiten Article: 221802
Bemerkung zur Veröffentlichung Gefördert durch SCOAP3
Vorab online veröffentlicht am 29.11.2018
Nachgewiesen in Scopus
Web of Science
KIT – Die Forschungsuniversität in der Helmholtz-Gemeinschaft
KITopen Landing Page