Exotic decays of heavy B quarks

Heavy vector-like quarks of charge -1/3, B, have been searched for at the LHC through the decays B -> bZ, bh, tW. In models where the B quark also carries charge under a new gauge group, new decay channels may dominate. We focus on the case where the B is charged under a U(1)' and describe simple models where the dominant decay mode is B -> bZ' -> b(b (b) over bar). With the inclusion of dark matter such models can explain the excess of gamma rays from the Galactic center. We develop a search strategy for this decay chain and estimate that with integrated luminosity of 300 fb(-1) the LHC will have the potential to discover both the B and the Z' for B quarks with mass below similar to 1 :6TeV, for a broad range of Z' masses. A high-luminosity run can extend this reach to 2 TeV.