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 s=7 and 8 TeV correspond to integrated luminosities of 5.0 and 19.7 fb−1, respectively. The analysis is performed using events with one muon and two or three jets. A Bayesian neural network technique is used to discriminate between the signal and backgrounds, which are observed 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 |fVR| < 0.16, |fTL| < 0.057, and − 0.049 < fTR < 0.048, respectively. For the FCNC couplings κtug and κtcg, the 95% CL upper limits on coupling strengths are |κtug|/Λ < 4.1 × 10− 3 TeV−1 and |κtcg|/Λ < 1.8 × 10− 2 TeV−1, where Λ is the scale for new physics, and correspond to upper limits on the branching fractions of 2.0 × 10−5 and 4.1 × 10−4 for the decays t → ug and t → cg, respectively.[Figure not available: see fulltext.]

Khachatryan, V., Sirunyan, A., Tumasyan, A., Adam, W., Asilar, E., Bergauer, T., et al. (2017). Search for anomalous Wtb couplings and flavour-changing neutral currents in t-channel single top quark production in pp collisions at √s=7 and 8 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2017(2) [10.1007/JHEP02(2017)028].

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

BRIANZA, LUCA;DINARDO, MAURO EMANUELE;FIORENDI, SARA;GHEZZI, ALESSIO;GOVONI, PIETRO;MANZONI, RICCARDO ANDREA;MARZOCCHI, BADDER;MORONI, LUIGI;PAGANONI, MARCO;PIGAZZINI, SIMONE;RAGAZZI, STEFANO;TABARELLI DE FATIS, TOMMASO;De Guio, F;Lucchini, M;
2017

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 s=7 and 8 TeV correspond to integrated luminosities of 5.0 and 19.7 fb−1, respectively. The analysis is performed using events with one muon and two or three jets. A Bayesian neural network technique is used to discriminate between the signal and backgrounds, which are observed 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 |fVR| < 0.16, |fTL| < 0.057, and − 0.049 < fTR < 0.048, respectively. For the FCNC couplings κtug and κtcg, the 95% CL upper limits on coupling strengths are |κtug|/Λ < 4.1 × 10− 3 TeV−1 and |κtcg|/Λ < 1.8 × 10− 2 TeV−1, where Λ is the scale for new physics, and correspond to upper limits on the branching fractions of 2.0 × 10−5 and 4.1 × 10−4 for the decays t → ug and t → cg, respectively.[Figure not available: see fulltext.]
Articolo in rivista - Articolo scientifico
Flavour Changing Neutral Currents; Hadron-Hadron scattering (experiments); Top physics; Nuclear and High Energy Physics
English
2017
2017
2
28
none
Khachatryan, V., Sirunyan, A., Tumasyan, A., Adam, W., Asilar, E., Bergauer, T., et al. (2017). Search for anomalous Wtb couplings and flavour-changing neutral currents in t-channel single top quark production in pp collisions at √s=7 and 8 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2017(2) [10.1007/JHEP02(2017)028].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/153062
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