Search for $s$-channel single top-quark production in proton–proton collisions at $\\sqrt s=8$ TeV with the ATLAS detector
Journal
Physics Letters
Journal Volume
B740
Pages
118-136
Date Issued
2015
Author(s)
Aad, Georges
Abstract
This Letter presents a search at the LHC for s-channel single top-quark production in proton-proton collisions at a centre-of-mass energy of 8 TeV. The analyzed data set was recorded by the ATLAS detector and corresponds to an integrated luminosity of 20.3 fb -1 . Selected events contain one charged lepton, large missing transverse momentum and exactly two b-tagged jets. A multivariate event classifier based on boosted decision trees is developed to discriminate s-channel single top-quark events from the main background contributions. The signal extraction is based on a binned maximum-likelihood fit of the output classifier distribution. The analysis leads to an upper limit on the s-channel single topquark production cross-section of 14.6 pb at the 95% confidence level. The fit gives a cross-section of s = 5.0 4.3 pb, consistent with the Standard Model expectation.
Type
journal article