Evidence for the associated production of a W boson and a top quark in ATLAS at root s=7 TeV

	Evidence for the associated production of a W boson and a top quark in ATLAS at root s=7 TeV
	ATLAS collaboration
刊名	PHYSICS LETTERS B
	2012
卷号	716 期号:1 页码:142-159
通讯作者	Arik, E (reprint author), Bogazici Univ, Dept Phys, Istanbul, Turkey.
英文摘要	This Letter presents evidence for the associated production of a W boson and a top quark using 2.05 fb(-1) of pp collision data at root s = 7 TeV accumulated with the ATLAS detector at the LHC. The analysis is based on the selection of the dileptonic final states with events featuring two isolated leptons, electron or muon, with significant transverse missing momentum and at least one jet. An approach based on boosted decision trees has been developed to improve the discrimination of single top-quark Wt events from background. A template fit to the final classifier distributions is performed to determine the cross-section. The result is incompatible with the background-only hypothesis at the 3.3 sigma level, the expected sensitivity assuming the Standard Model production rate being 3.4 sigma. The corresponding cross-section is determined and found to be sigma(wt) = 16.8 +/- 2.9 (stat) +/- 4.9 (syst) pb, in good agreement with the Standard Model expectation. From this result the CKM matrix element vertical bar V-tb vertical bar = 1.03(-0.19)(+0.16) is derived assuming that the Wt production through vertical bar V-ts vertical bar and vertical bar V-td vertical bar is small. (C) 2012 CERN. Published by Elsevier B.V All rights reserved.
学科主题	Physics
类目[WOS]	Physics, Multidisciplinary
收录类别	SCI
语种	英语
WOS记录号	WOS:000309621400007
公开日期	2016-02-26
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/213345]
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. Evidence for the associated production of a W boson and a top quark in ATLAS at root s=7 TeV[J]. PHYSICS LETTERS B,2012,716(1):142-159.
APA	ATLAS collaboration.(2012).Evidence for the associated production of a W boson and a top quark in ATLAS at root s=7 TeV.PHYSICS LETTERS B,716(1),142-159.
MLA	ATLAS collaboration."Evidence for the associated production of a W boson and a top quark in ATLAS at root s=7 TeV".PHYSICS LETTERS B 716.1(2012):142-159.