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

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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.

Autore Pugliese

Tutti gli autori

  • G. AAD , G. CHIODINI , E. GORINI , M. PRIMAVERA , S. SPAGNOLO , A. VENTURA

Titolo volume/Rivista

PHYSICS LETTERS. SECTION B

Anno di pubblicazione

2016

ISSN

0370-2693

ISBN

Non Disponibile

Numero di citazioni Wos

10

Ultimo Aggiornamento Citazioni

22/04/2018

Numero di citazioni Scopus

17

Ultimo Aggiornamento Citazioni

22/04/2018

Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile