LHC Signatures of Vector-Like Quarks

Figure 3

Feynman diagrams for FCNC top decays into 𝑔𝑞 in the SM (left) and induced at loop level by the presence of VLQs (centre and right). In the diagrams, 𝑢_𝑖=𝑢,𝑐,𝑡,𝑡^′ and 𝑑_𝑖=𝑑,𝑠,𝑏,𝑏^′.