Search for Flavor-Changing Neutral Currents in Top-Quark Decays t → Zq in pp Collisions at √s = 8 TeV

Search for Flavor-Changing Neutral Currents in Top-Quark Decays t → Zq in pp Collisions at √s = 8 TeV

A search for flavor-changing neutral currents in top-quark decays t → Zq is performed in events produced from the decay chain t[bar over t] → 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 detec...

Full description

Bibliographic Details
Main Authors: Apyan, Aram, Barbieri, Riccardo, Bauer, Gerry P., Busza, Wit, Cali, Ivan Amos, Chan, M., Di Matteo, Leonardo, Dutta, V., Gomez-Ceballos, Guillelmo, Goncharov, Maxim, Gulhan, Doga Can, Klute, Markus, Lai, Yue Shi, Lee, Y.-J., Levin, A., Luckey, P. David, Jr., Ma, Teng, Paus, Christoph M. E., Ralph, Duncan Kelley, Roland, Christof E., Roland, Gunther M., Stephans, George S. F., Stockli, Fabian, Sumorok, Konstanty C., Velicanu, Dragos Alexandru, Veverka, Jan, Wyslouch, Boleslaw, Yang, M., Yoon, A. S., Zanetti, Marco, Zhukova, Victoria
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:en_US
Published: American Physical Society 2014
Online Access:http://hdl.handle.net/1721.1/88724
https://orcid.org/0000-0002-3831-9071
https://orcid.org/0000-0003-3106-4894
https://orcid.org/0000-0001-6332-5839
https://orcid.org/0000-0001-8983-2169
https://orcid.org/0000-0002-1260-777X
https://orcid.org/0000-0002-6047-4211
https://orcid.org/0000-0002-7945-005X
https://orcid.org/0000-0003-3681-0649
https://orcid.org/0000-0002-9418-6656
https://orcid.org/0000-0003-1486-606X
https://orcid.org/0000-0003-2593-7767
https://orcid.org/0000-0001-9236-6621
https://orcid.org/0000-0002-0869-5631
https://orcid.org/0000-0002-1136-6900
Description
Summary:A search for flavor-changing neutral currents in top-quark decays t → Zq is performed in events produced from the decay chain t[bar over t] → 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[superscript −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.

Similar Items