Observation of Single Top Quark Production in Association with a Z Boson in Proton-Proton Collisions at root s=13 TeV
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Dosyalar
Tarih
2019-04-05
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Dergi Başlığı
Dergi ISSN
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Yayıncı
AMER PHYSICAL SOC
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
The observation of single top quark production in association with a Z boson and a quark (tZq) is reported. Events from proton-proton collisions at a center-of-mass energy of 13 TeV containing three charged leptons (either electrons or muons) and at least two jets are analyzed. The data were collected with the CMS detector in 2016 and 2017 and correspond to an integrated luminosity of 77.4fb(-1). The increased integrated luminosity, a multivariate lepton identification, and a redesigned analysis strategy improve significantly the sensitivity of the analysis compared to previous searches for tZq production. The tZq signal is observed with a significance well over 5 standard deviations. The measured tZq production cross section is sigma(pp -> tZq -> tl(+) l(-) q) = 111 +/- 13 (stat)(-9)(+11) (syst) fb, for dilepton invariant masses above 30 GeV, in agreement with the standard model expectation.
Açıklama
Anahtar Kelimeler
Kaynak
PHYSICAL REVIEW LETTERS
WoS Q Değeri
Q1
