Search for ttbar resonances in the lepton plus jets final state in ppbar collisions at sqrt{s}=1.96TeV

TL;DR

This paper searches for narrow heavy resonances decaying into top quark pairs in proton-antiproton collisions at 1.96 TeV, using data from the D0 detector, and sets limits on possible new particles.

Contribution

It presents the first search for ttbar resonances in the lepton plus jets channel at the Tevatron and sets exclusion limits on specific models like leptophobic Z' bosons.

Findings

No evidence for narrow ttbar resonances was found.

Upper limits were set on the production cross section times branching ratio.

A leptophobic Z' boson with mass below 700 GeV is excluded at 95% confidence level.

Abstract

We present a search for a narrow-width heavy resonance decaying into top quark pairs X->ttbar in ppbar collisions at sqrt{s}=1.96TeV using approximately 0.9fb^-1 of data collected with the D0 detector at the Fermilab Tevatron Collider. This analysis considers ttbar candidate events in the lepton plus jets channel with at least one identified b jet and uses the ttbar invariant mass distribution to search for evidence of resonant production. We find no evidence for a narrow resonance X decaying to ttbar. Therefore, we set upper limits on sigma*B(X->ttbar) for different hypothesized resonance masses using a Bayesian approach. For a Topcolor-assisted technicolor model, the existence of a leptophobic Z' boson with mass M_Z'<700GeV and width Gamma_Z'=0.012 M_Z' can be excluded at the 95% C.L.