6533b860fe1ef96bd12c369c

RESEARCH PRODUCT

Search for FCNC single top-quark production at root s=7 TeV with the ATLAS detector

Atlas CollaborationVasiliki MitsouJuan A. Fuster VerdúAntonio Ferrer SoriaMaría Victoria Castillo GiménezSusana Cabrera UrbánCarmen García GarcíaEmilio Higón RodríguezSalvador Martí GarcíaEduardo Ros MartínezSantiago González De La HozJosé Salt CairolsJuan Antonio Valls FerrerMohammed KaciLuca FioriniYesenia Hernández JiménezCarlos Lacasta LlácerMiguel Villaplana Pérez

subject

Acceleradors de partículesHigh Energy Physics::ExperimentPartícules (Física nuclear)Detectors de radiació

description

A search for the production of single top-quarks via flavour-changing neutral-currents is presented. Data collected with the ATLAS detector at a centre-of-mass energy of root s = 7 TeV, corresponding to an integrated luminosity of 2.05 fb(-1), are used. Candidate events with a semileptonic top-quark decay signature are classified as signal- or background-like events by using several kinematic variables as input to a neural network. No signal is observed in the neural network output distribution and a Bayesian upper limit is placed on the production cross-section. The observed upper limit at 95% confidence level on the cross-section multiplied by the t -> Wb branching fraction is measured to be sigma(qg -> t) x B(t -> Wb) ug) cg) < 2.7.10(-4).

10.1016/j.physletb.2012.05.022http://hdl.handle.net/10550/36380