Search for single top quarks in the tau+jets channel using 4.8 fb.sup.-1./sup. of p p-bar collision data

0352066 - FZÚ 2011 RIV NL eng J - Journal Article
Abazov, V. M. - Abbott, B. - Abolins, M. - Kupčo, Alexander - Lokajíček, Miloš
Search for single top quarks in the tau+jets channel using 4.8 fb^-1 of p p-bar collision data.
Physics Letters. B. Roč. 690, č. 1 (2010), s. 5-14. ISSN 0370-2693. E-ISSN 1873-2445
R&D Projects: GA MŠMT LC527; GA MŠMT LA08047
Institutional research plan: CEZ:AV0Z10100502
Keywords : D0 * quark * collisions * lepton
Subject RIV: BF - Elementary Particles and High Energy Physics
Impact factor: 5.255, year: 2010
http://arxiv.org/abs/0912.1066

We present the first direct search for single top quark production using tau leptons. The search is based on 4.8 fb^-1$ of integrated luminosity collected in $p/bar{p}$ collisions at $/sqrt{s}$=1.96 TeV with the D0 detector at the Fermilab Tevatron Collider. We select events with a final state including an isolated tau lepton, missing transverse energy, two or three jets, one or two of them $b$ tagged. We use a multivariate technique to discriminate signal from background. The number of events observed in data in this final state is consistent with the signal plus background expectation. We set in the tau+jets channel an upper limit on the single top quark cross section of /TauLimObs pb at the 95% C.L. This measurement allows a gain of 4% in expected sensitivity for the observation of single top production when combining it with electron+jets and muon+jets channels already published by the D0 collaboration with 2.3 fb^-1$ of data.
Permanent Link: http://hdl.handle.net/11104/0191663