Search for heavy narrow resonances decaying to ttbar in the muon+jets channel

A search for narrow heavy resonances decaying to top quark pairs is performed using a data sample of pp collisions collected by the CMS experiment at the LHC at $\sqrt{s} = 7$~TeV corresponding to an integrated luminosity of $1.14 \pm 0.05~{\rm fb}^{-1}$. This search considers a sample of $\rm t\bar t$ candidates in the muon+jets topology, $\rm t\bar t \rightarrow (W^{+}b)(W^{-}\bar{b})\rightarrow (q\bar{q}'b)$$( \mu^{-}\bar{\nu} \rm \bar{b})$ (or charge conjugate), and focuses on heavy resonances resulting in energetic top quarks whose decay products are narrowly collimated. To cope with this topology, a dedicated event selection and reconstruction of the invariant $\rm t\bar t$ mass is deployed. Sub-picobarn limits (at 95\% confidence level) are set on $\sigma(\rm pp \rightarrow Z^\prime \rightarrow t\bar t)$ for invariant $\rm Z^\prime$ masses above $1.35~\text{TeV}/c^2$.