## Abstract

 We performed a search for non-standard model $t \bar t$ resonances in the all jets final state channel. The main goal was to examine top-antitop invariant mass spectrum for the presence of narrow resonant states. The data analysis used 2.8$fb^{-1}$ of CDF data; events were produced at the Tevatron collider in $p \bar p$ collisions with center-of-mass energy of 1.96 TeV. 2086 data events were analyzed and compared to Standard Model expectation. No evidence for new $t \bar t$ resonant production mechanisms was found. Upper limits were placed on the cross-section times branching ratio for resonance production at 805 $GeV/c^2$. For signal modeling we considered leptophobic Z' boson in a topcolor-assisted technicolor model with the width of $\Gamma = 1.2$\%$M_{X0}$.