Many beyond the standard model extensions predict the existence of heavy vectorlike fermions. We study the LHC signatures of one such heavy vectorlike fermion, called $b^{\prime }$, with electromagnetic charge $-1/3$ like the SM $b$-quark, but which could generically have different $SU(2{)}_L$ and $U(1{)}_Y$ quantum numbers. Our emphasis will be on the phenomenology due to $b\leftrightarrow b^{\prime }$ mass mixing, present after electroweak symmetry breaking. We focus on aspects which distinguish a vectorlike $b^{\prime }$ from a chiral $b^{\prime }$ and include tree-level decays of the $b^{\prime }$ into $tW$, $bZ$ and $bh$ final states. While our analysis is largely model independent, we take as a motivating example warped-space models in which a vectorlike $b^{\prime }$ appears as the custodial partner of the top-quark.

• Received 29 July 2011

DOI:https://doi.org/10.1103/PhysRevD.84.055001