Search for pair-produced vector-like top quark partners decaying to bW in the fully hadronic channel using jet substructure at 8 TeV

We present a search for pair-produced vector-like top quark partners in 19.7~fb$^{-1}$ of $\rm pp$ collisions at $\sqrt{s} = 8$ TeV collected with the CMS detector at the LHC in 2012. The search is optimized for the decay mode $\rm T \to bW$ in the fully hadronic final state. Due to the large mass of the $\rm T$ quark, its decay products are significantly boosted, requiring the use of specialized jet substructure techniques. We select events with four jets, of which two are assigned to the hadronic W boson decay and the others are consistent with the hadronization of a b quark. We see no excess of events above the expected standard model backgrounds and set limits on the $\rm T$ pair-production cross section. $\rm T$ quarks with masses below 705 GeV/$c^2$ are excluded at the 95\% confidence level. We also set limits on the $\rm T \to tZ$ and $\rm T \to tH$ decays.