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
Publisher DOI
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.
Date Issued
2016
Publication Type
Article
Subject(s)
Language(s)
en
Author(s)
Mullier, Geoffrey | |
Meloni, Federico | |
Cervelli, Alberto | |
Stucci, Stefania | |
Ereditato, Antonio |
Additional Credits
Journal
Physics letters. B
Publisher
Elsevier
ISSN
0370-2693
Access(Rights)
open.access