Heavy Vector-like Top Partners at the LHC and flavour constraints
  We consider the phenomenology at the Large Hadron Collider of new heavy vector-like quarks which couple mainly to the third generation quarks via Yukawa interactions, with special emphasis on non-standard doublet representations which are less constrained from present data. We also discuss in detail the flavour limits at tree level and loop level and implications of a generalised CKM mixing matrix to these cases. 
Giacomo Cacciapaglia, Aldo Deandrea, Naveen Gaur, Daisuke Harada,   Yasuhiro Okada and Luca Panizzi
hep-ph