Studies on Top Quark Flavor-changing Neutral-current Decays at CMS
Yuan CHAO1*, I-Huan CHIU1
1Department of Physics, National Taiwan University, Taipei, Taiwan
* presenting author:Yuan CHAO,
Searches for the flavor-changing neutral-current (FCNC) process in top-quark decays, t → qZ and t → qH, is reported using a data sample of 19.8/fb collected in proton-proton collision at the center-of-mass energy of 8 TeV with the CMS detector at the LHC. The analysis is performed by tagging a top-quark decaying into a b-quark and a W boson, identified with a lepton and a neutrino, and searching for a di-lepton or di-b pair from Z-boson and Higgs decay and a light quark in the event. No significant signal is observed. The branching fraction upper limits of t → qZ and t → qH are determined.

Keywords: LHC, CMS, Top quark, FCNC, Higgs