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

Mullier, Geoffrey; Haug, Sigve; Weber, Michael; Meloni, Federico; Cervelli, Alberto; Beck, Hans Peter; Stucci, Stefania; Ereditato, Antonio (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. Elsevier 10.1016/j.physletb.2016.03.017

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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 (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Laboratory for High Energy Physics (LHEP)

UniBE Contributor:

Haug, Sigve; Weber, Michael and Beck, Hans Peter

Subjects:

500 Science > 530 Physics
500 Science > 510 Mathematics

ISSN:

0370-2693

Publisher:

Elsevier

Language:

English

Submitter:

Annette Krebs-Wegenast

Date Deposited:

15 Aug 2017 07:36

Last Modified:

15 Aug 2017 07:36

Publisher DOI:

10.1016/j.physletb.2016.03.017

Additional Information:

Kollaboration - Es sind nur die Berner Autoren namentlich erwähnt.

BORIS DOI:

10.7892/boris.100002

URI:

https://boris.unibe.ch/id/eprint/100002

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