Evidence for single top-quark production in the s-channel in proton–proton collisions at √s = 8TeV with the ATLAS detector using the Matrix Element Method
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 σ s = 4.8 ± 0.8(stat.) -1.3 +1.6(syst.) pb, which is consistent with the Standard Model expectation. As a result, the expected significance for the analysis is 3.9 standard deviations.
- Authors:
-
[1]
- Aix-Marseille Univ. and CNRS/IN2P3, Marseille (France). et al.
- Publication Date:
- Grant/Contract Number:
- AC02-76SF00515; AC02-05CH11231
- Type:
- Published Article
- Journal Name:
- Physics Letters. Section B
- Additional Journal Information:
- Journal Volume: 756; Journal Issue: C; Journal ID: ISSN 0370-2693
- Publisher:
- Elsevier
- Research Org:
- SLAC National Accelerator Lab., Menlo Park, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Org:
- USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
- Contributing Orgs:
- ATLAS Collaboration
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
- OSTI Identifier:
- 1241427
- Alternate Identifier(s):
- OSTI ID: 1242386; OSTI ID: 1379336