Search for flavour-changing neutral current top-quark decays t -> qZ in proton-proton collisions at root s=13 TeV with the ATLAS detector

doi:10.1007/JHEP07(2018)176

	Search for flavour-changing neutral current top-quark decays t -> qZ in proton-proton collisions at root s=13 TeV with the ATLAS detector
	ATLAS Collaboration
刊名	JOURNAL OF HIGH ENERGY PHYSICS
	2018
期号	7 页码:176
关键词	Hadron-Hadron scattering (experiments)
ISSN号	1029-8479
DOI	10.1007/JHEP07(2018)176
文献子类	Article
英文摘要	A search for flavour-changing neutral-current processes in top-quark decays is presented. Data collected with the ATLAS detector from proton-proton collisions at the Large Hadron Collider at a centre-of-mass energy of root s = 13TeV, corresponding to an integrated luminosity of 36.1 fb(-1), are analysed. The search is performed using top-quark pair events, with one top quark decaying through the t -> qZ (q = u, c) flavour-changing neutral-current channel, and the other through the dominant Standard Model mode t -> bW. Only Z boson decays into charged leptons and leptonic W boson decays are considered as signal. Consequently, the final-state topology is characterized by the presence of three isolated charged leptons (electrons or muons), at least two jets, one of the jets originating from a b-quark, and missing transverse momentum from the undetected neutrino. The data are consistent with Standard Model background contributions, and at 95% confidence level the search sets observed (expected) upper limits of 1.7 x 10(-4) (2.4 x 10(-4)) on the t -> uZ branching ratio and 2.4 x 10(-4) (3.2 x 10(-4)) on the t -> cZ branching ratio, constituting the most stringent limits to date.
WOS关键词	PARTON DISTRIBUTIONS ; PLUS PLUS ; HADRON COLLIDERS ; PAIR-PRODUCTION ; CROSS-SECTION ; HERWIG PLUS ; LHC ; PHYSICS ; MODELS ; LEP
WOS研究方向	Physics
语种	英语
WOS记录号	WOS:000443814800001
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/286312]
专题	高能物理研究所_实验物理中心
作者单位	中国科学院高能物理研究所
推荐引用方式 GB/T 7714	ATLAS Collaboration. Search for flavour-changing neutral current top-quark decays t -> qZ in proton-proton collisions at root s=13 TeV with the ATLAS detector[J]. JOURNAL OF HIGH ENERGY PHYSICS,2018(7):176.
APA	ATLAS Collaboration.(2018).Search for flavour-changing neutral current top-quark decays t -> qZ in proton-proton collisions at root s=13 TeV with the ATLAS detector.JOURNAL OF HIGH ENERGY PHYSICS(7),176.
MLA	ATLAS Collaboration."Search for flavour-changing neutral current top-quark decays t -> qZ in proton-proton collisions at root s=13 TeV with the ATLAS detector".JOURNAL OF HIGH ENERGY PHYSICS .7(2018):176.