A search for flavor-changing neutral currents in top-quark decays t→Zq is performed in events produced from the decay chain tt¯→Zq+Wb, where both vector bosons decay leptonically, producing a final state with three leptons (electrons or muons). A data set collected with the CMS detector at the LHC is used, corresponding to an integrated luminosity of 19.7  fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. No excess is seen in the observed number of events relative to the standard model prediction; thus, no evidence for flavor-changing neutral currents in top-quark decays is found. A combination with a previous search at 7 TeV excludes a t→Zq branching fraction greater than 0.05% at the 95% confidence level.

S. Chatrchyan, V. Khachatryan, A. M. Sirunyan, A. Tumasyan, W. Adam, T. Bergauer, et al. (2014). Search for Flavor-Changing Neutral Currents in Top-Quark Decays t to Zq in pp collisions at sqrt(s) = 8 TeV. PHYSICAL REVIEW LETTERS, 112, 171802-1-171802-16 [10.1103/PhysRevLett.112.171802].

Search for Flavor-Changing Neutral Currents in Top-Quark Decays t to Zq in pp collisions at sqrt(s) = 8 TeV

BONACORSI, DANIELE;BRAIBANT, SYLVIE;BRIGLIADORI, LUCA;CAMPANINI, RENATO;CAPILUPPI, PAOLO;CASTRO, ANDREA;CODISPOTI, GIUSEPPE;CUFFIANI, MARCO;FANFANI, ALESSANDRA;FASANELLA, DANIELE;GUIDUCCI, LUIGI;MENEGHELLI, MARCO;PRIMAVERA, FEDERICA;ROVELLI, TIZIANO;SIROLI, GIAN PIERO;TOSI, NICOLÒ;C. Battilana;
2014

Abstract

A search for flavor-changing neutral currents in top-quark decays t→Zq is performed in events produced from the decay chain tt¯→Zq+Wb, where both vector bosons decay leptonically, producing a final state with three leptons (electrons or muons). A data set collected with the CMS detector at the LHC is used, corresponding to an integrated luminosity of 19.7  fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. No excess is seen in the observed number of events relative to the standard model prediction; thus, no evidence for flavor-changing neutral currents in top-quark decays is found. A combination with a previous search at 7 TeV excludes a t→Zq branching fraction greater than 0.05% at the 95% confidence level.
2014
S. Chatrchyan, V. Khachatryan, A. M. Sirunyan, A. Tumasyan, W. Adam, T. Bergauer, et al. (2014). Search for Flavor-Changing Neutral Currents in Top-Quark Decays t to Zq in pp collisions at sqrt(s) = 8 TeV. PHYSICAL REVIEW LETTERS, 112, 171802-1-171802-16 [10.1103/PhysRevLett.112.171802].
S. Chatrchyan;V. Khachatryan;A. M. Sirunyan;A. Tumasyan;W. Adam;T. Bergauer;M. Dragicevic;J. Erö;C. Fabjan;M. Friedl;R. Frühwirth;V. M. Ghete;C. Hartl...espandi
File in questo prodotto:
Eventuali allegati, non sono esposti

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/369331
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 87
  • ???jsp.display-item.citation.isi??? 91
social impact