Evidence for single top-quark production in the s -channel in proton–proton collisions at √s=8 TeV with the ATLAS detector using the Matrix Element Method

, The ATLAS collaboration (2016) Evidence for single top-quark production in the s -channel in proton–proton collisions at √s=8 TeV with the ATLAS detector using the Matrix Element Method. Physics Letters B, 756. pp. 228-246. ISSN 0370-2693

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Abstract

This Letter presents evidence for single top-quark production in the s -channel using proton–proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS detector at the CERN Large Hadron Collider. The analysis is performed on events containing one isolated electron or muon, large missing transverse momentum and exactly two b -tagged jets in the final state. The analysed data set corresponds to an integrated luminosity of 20.3 fb−1. The signal is extracted using a maximum-likelihood fit of a discriminant which is based on the matrix element method and optimized in order to separate single-top-quark s-channel events from the main background contributions, which are top-quark pair production and W boson production in association with heavy-flavour jets. The measurement leads to an observed signal significance of 3.2 standard deviations and a measured cross-section of σs = 4.8 ± 0.8(stat.)+1.6 −1.3(syst.) pb, which is consistent with the Standard Model expectation. The expected significance for the analysis is 3.9 standard deviations.

Item Type:
Journal Article
Journal or Publication Title:
Physics Letters B
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/3100/3106
Subjects:
ID Code:
79615
Deposited By:
Deposited On:
17 May 2016 14:26
Refereed?:
Yes
Published?:
Published
Last Modified:
21 Oct 2020 04:06