A Search for Resonances in Semileptonic Top Pair Production

We present the results of a search for massive neutral bosons decaying via a top-antitop quark pair. The analysis is carried out using 4.7~fb$^{-1}$ of proton-proton collision data at a centre-of-mass energy of 7~TeV collected by the CMS detector at the LHC during 2011. From a combined analysis of the muon plus jets and electron plus jets decay modes no significant signal is observed. A leptophobic topcolor \zp with width much less than the detector resolution is excluded for masses below 1.3~TeV$/c^2$, a leptophobic topcolor \zp with width 10\% of its mass is excluded below 1.7~TeV$/c^2$, and a Kaluza-Klein gluon is excluded with a mass below 1.4~TeV$/c^2$.