Ústav technické a experimentální fyziky Institute of Experimental and Applied Physics

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

NázevTitle
Search for FCNC single top-quark production at root s=7 TeV with the ATLAS detectorSearch for FCNC single top-quark production at root s=7 TeV with the ATLAS detector
Druh výsledkuResult type
Článek v časopiseJournal article
AutořiAuthors
G. Aad, B. Abbott, J. Abdallah, A. A. Abdelalim, A. Abdesselam, K. Augsten, T. Holý, T. Horažďovský, Z. Hubáček, J. Jakůbek, Z. Kohout, V. Král, F. Krejčí, S. Pospíšil, V. Šimák, T. Slavíček, K. Smolek, J. Sodomka, M. Solar, J. Šolc, B. Sopko, V. Sopko, I. Štekl, D. Tureček, V. Vacek, M. Vlasák, P. Vokáč
DOIDOI
10.1016/j.physletb.2012.05.022
Časopis / citaceJournal / citation
Physics Letters B. 2012, 712(4-5), 351-369. ISSN 0370-2693.
RokYear
2012
JazykLanguage
eng
WoSWoS
000305378200006
ScopusScopus
2-s2.0-85041997804
RIVRIV
RIV/68407700:21220/12:00202612!RIV13-MSM-21220___
ProjektProject
Fundamentální experimenty ve fyzice mikrosvětaFundamental Experiments in Physics of Microworld; Mezinárodní experiment ATLAS-CERNInternational Experiment ATLAS-CERN; Mezinárodní experiment ATLAS-CERNInternational Experiment ATLAS-CERN; Matematické, počítačové a experimentální metody ve fyziceMathematical, Computer and Experimental Methods in Physics; Centrum částicové fyzikyCenter for Particle Physics; Matematické, počítačové a experimentální metody ve fyziceMathematical, Computer and Experimental Methods in Physics

AbstraktAbstract

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) < 3.9 pb. This upper limit is converted using a model-independent approach into upper limits on the coupling strengths kappa(ugt)/Lambda < 6.9.10(-3) TeV-1 and kappa(cgt)/Lambda < 1.6.10(-2) TeV-1, where A is the new physics scale, and on the branching fractions B(t -> ug) < 5.7.10(-5) and B(t -> cg) < 2.7.10(-4).

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) < 3.9 pb. This upper limit is converted using a model-independent approach into upper limits on the coupling strengths kappa(ugt)/Lambda < 6.9.10(-3) TeV-1 and kappa(cgt)/Lambda < 1.6.10(-2) TeV-1, where A is the new physics scale, and on the branching fractions B(t -> ug) < 5.7.10(-5) and B(t -> cg) < 2.7.10(-4).