# Search for anomalous Wtb couplings and flavour-changing neutral currents in t-channel single top quark production in pp collisions at sqrt(s) = 7 and 8 TeV

Abstract : Single top quark events produced in the t channel are used to set limits on anomalous Wtb couplings and to search for top quark flavour-changing neutral current (FCNC) interactions. The data taken with the CMS detector at the LHC in proton-proton collisions at sqrt(s) = 7 and 8 TeV correspond to integrated luminosities of 5.0 and 19.7 inverse-femtobarns, respectively. The analysis is performed using events with one muon and two or three jets. A Bayesian neural network technique, used to discriminate between the signal and backgrounds, is found to be consistent with the standard model prediction. The 95% confidence level (CL) exclusion limits on anomalous right-handed vector, and left- and right-handed tensor Wtb couplings are measured to be |f[V]^R| < 0.16, |f[T]^L| < 0.057, and -0.049 < f[T]^R < 0.048, respectively. For the FCNC couplings kappa[tug] and kappa[tcg], the 95% CL upper limits on coupling strengths are |kappa[tug]|/Lambda < 4.1E-3 TeV-1 and |kappa[tcg]|/Lambda < 1.8E-2 TeV-1, where Lambda is the scale for new physics, and correspond to upper limits on the branching fractions of 2.0E-5 and 4.1E-4 for the decays t to ug and t to cg, respectively.
Keywords :
Type de document :
Article dans une revue
Journal of High Energy Physics, Springer Verlag (Germany), 2017, 02 (2), pp.028. 〈10.1007/JHEP02(2017)028〉

http://hal.in2p3.fr/in2p3-01380410
Contributeur : Dominique Girod <>
Soumis le : mardi 18 décembre 2018 - 09:04:13
Dernière modification le : jeudi 7 février 2019 - 15:28:24

### Fichier

HAL-01380410.pdf
Fichiers éditeurs autorisés sur une archive ouverte

### Citation

V. Khachatryan, M. Besancon, F. Couderc, M. Dejardin, D. Denegri, et al.. Search for anomalous Wtb couplings and flavour-changing neutral currents in t-channel single top quark production in pp collisions at sqrt(s) = 7 and 8 TeV. Journal of High Energy Physics, Springer Verlag (Germany), 2017, 02 (2), pp.028. 〈10.1007/JHEP02(2017)028〉. 〈in2p3-01380410〉

### Métriques

Consultations de la notice

## 287

Téléchargements de fichiers