par Aaltonen, Timo;De Lentdecker, Gilles ; [et al.]
Référence Physical review. D, Particles, fields, gravitation, and cosmology, 77, 5, 051102
Publication Publié, 2008-03
Article révisé par les pairs
Résumé : We search for evidence of resonant top quark pair production in 955 pb-1 of pp̄ collisions at s=1.96TeV recorded with the CDF II detector at the Fermilab Tevatron. For fully reconstructed candidate tt̄ events triggered on leptons with large transverse momentum and containing at least one identified b-quark jet, we compare the invariant mass spectrum of tt̄ pairs to the expected superposition of standard model tt̄, non-tt̄ backgrounds, and a simple resonance model based on a sequential Z′ boson. We establish upper limits for σ(pp̄→Z′) ·Br(Z′→tt̄) in the Z′ mass interval from 450GeV/c2 to 900GeV/c2. A topcolor leptophobic Z′ is ruled out below 720GeV/c2, and the cross section of any narrow Z′-like state decaying to tt̄ is found to be less than 0.64 pb at 95% C.L. for MZ′ above 700GeV/c2. © 2008 The American Physical Society.