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 top- quark production cross-section of 14.6 pb at the 95% confidence level. The fit gives a cross-section of σs = 5.0 ± 4.3 pb, consistent with the Standard Model expectation.
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Titolo: | Search for s-channel single top-quark production in proton–proton collisions at √s = 8 TeV with the ATLAS detector | |
Autori: | ||
Data di pubblicazione: | 2015 | |
Rivista: | ||
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 top- quark production cross-section of 14.6 pb at the 95% confidence level. The fit gives a cross-section of σs = 5.0 ± 4.3 pb, consistent with the Standard Model expectation. | |
Handle: | http://hdl.handle.net/11571/985094 | |
Appare nelle tipologie: | 1.1 Articolo in rivista |