Measurements of new physics in top quark decay at LHC

A summary of ATLAS and CMS results on searches for new physics in top quark decay is presented. Three analysis are reported: the ATLAS and CMS searches for flavor changing neutral currents (FCNC) in top-quark decays and the CMS search for baryon number violation (BNV) in top-quark decays. ATLAS and CMS provided exclusion limits (at 95% CL) on the FCNC decay t → Zq, using respectively 2.1 fb−1 and 5.0 fb−1 of pp collisions at = 7 TeV collected in 2011. Upper limits on B(t → Zq) are respectively 0.73% and 0.24%. CMS has also set an exclusion limit (at 95% CL) on the BNV decay t → lbq using 5.0 fb−1 of data. Upper limit on B(t → lbq) is 0.67%.