Search for resonant top-antitop production in the lepton plus jets decay mode using the full CDF data set

Area of Science:

• High Energy Physics
• Particle Physics
• Collider Physics

Background:

• Searches for new physics beyond the Standard Model are crucial for understanding fundamental forces.
• Resonant states decaying into W bosons and b quarks are predicted by various theoretical extensions.
• Top-antitop (tt) resonances are a key target in searches for new heavy particles.

Purpose of the Study:

• To search for a narrow resonant state decaying into two W bosons and two b quarks.
• To investigate top-antitop resonant production at the Fermilab Tevatron.
• To set exclusion limits on the production cross section of such hypothetical particles.

Main Methods:

• Analysis of proton-antiproton collision data collected by the CDF II detector.
• Utilizing a full dataset corresponding to an integrated luminosity of 9.45 fb(-1) at a center-of-mass energy of 1.96 TeV.
• Searching for a specific decay channel: one W boson decaying leptonically and the other into a quark-antiquark pair.

Main Results:

• No significant evidence for a narrow resonant state was observed.
• Upper limits were placed on the product of the production cross section and branching ratio for a narrow resonant state.
• Exclusion of a Z' boson with a mass below 915 GeV/c^2 decaying into a top-antitop pair at the 95% credibility level.

Conclusions:

• The search provides the most sensitive limits to date for narrow qq-initiated tt resonances below 750 GeV/c^2.
• The results constrain theories predicting such new heavy particles.
• The absence of a signal indicates that new physics, if present in this channel, must lie at higher masses or have different properties.