Search for a vectorlike quark with charge 2/3 in t+Z events from pp collisions at √s=7 TeV.

Journal article

A search for pair-produced heavy vectorlike charge-2/3 quarks, T, in pp collisions at a center-of-mass energy of 7 TeV, is performed with the CMS detector at the LHC. Events consistent with the flavor-changing-neutral-current decay of a T quark to a top quark and a Z boson are selected by requiring two leptons from the Z-boson decay, as well as an additional isolated charged lepton. In a data sample corresponding to an integrated luminosity of 1.14  fb(-1), the number of observed events is found to be consistent with the standard model background prediction. Assuming a branching fraction of 100% for the decay T→tZ, a T quark with a mass less than 475  GeV/c(2) is excluded at the 95% confidence level.

Authors: Chatrchyan, S; Khachatryan, V; Sirunyan, A; Tumasyan, A; Adam, W

• Journal: Physical Review Letters
• Volume: 107
• Issue: 27
• Pages: 271802
• Publication date: 2011-12-01
• DOI: 10.1103/physrevlett.107.271802
• EISSN: 1079-7114
• ISSN: 0031-9007
• Language: English
• Keywords: CMS Collaboration