Search for BSM \ttbar Production in the Boosted All-Hadronic Final State

A search is presented for a massive particle or resonance, generically referred to as a $\zp$, decaying into a $t\bar{t}$ pair. The search focuses on $\zp$ resonances which are sufficiently heavy to result in energetic top quarks with decay products partially or fully merged into one jet. The analysis relies on new developments in the area of jet substructure and uses those techniques to suppress QCD background. The analysis is performed in proton-proton collisions corresponding to a luminosity of $886$ pb$^{-1}$. Sub-picobarn limits are set on $\sigma_{\zp} \times BR(\zp \to \ttbar)$ for $\zp$ heavier than $1.1$~$\TeVcc$. A Randall-Sundrum Kaluza-Klein gluon with mass between 1.0 and 1.5 $\TeVcc$ is also excluded at 95\% C.L.