Search for flavor changing neutral currents via quark-gluon couplings in single top quark production using 2.3 fb.sup.-1./sup. of ppbar collisions

0352065 - FZÚ 2011 RIV NL eng J - Journal Article
Abazov, V. M. - Abbott, B. - Abolins, M. - Kupčo, Alexander - Lokajíček, Miloš
Search for flavor changing neutral currents via quark-gluon couplings in single top quark production using 2.3 fb^-1 of ppbar collisions.
Physics Letters. B. Roč. 693, č. 2 (2010), s. 81-87. ISSN 0370-2693. E-ISSN 1873-2445
R&D Projects: GA MŠMT LC527; GA MŠMT LA08047
Institutional research plan: CEZ:AV0Z10100502
Keywords : top quark * single top * FCNC * flavor-changing neutral current * quark–gluon coupling * tevatron * proton–antiproton collider
Subject RIV: BF - Elementary Particles and High Energy Physics
Impact factor: 5.255, year: 2010
http://arxiv.org/abs/arXiv:1006.3575

We present a search for flavor changing neutral currents via quark-gluon couplings in a sample of single top quark final states corresponding to 2.3 fb^-1 of integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider. We select events containing a single top quark candidates with an additional jet, and obtain separation between signal and background using Bayesian neural networks. We find consistency between background expectation and observed data, and set limits on flavor changing neutral current gluon couplings of the top quark to up quarks (tgu) and charm quarks (tgc). The cross section limits at the 95% C.L. are sigma_tgu<0.20pb and sigma_tgc<0.27pb. These correspond to limits on the top quark decay branching fractions of B(t->gu)<2.0*10^-4 and B(t->gc)<3.9*10^-3.
Permanent Link: http://hdl.handle.net/11104/0191662