Search for Bs0→μ+μ- and B0→μ+μ- decays with 2fb-1 of pp̄ collisions
Physical Review Letters 100:10 (2008)
Abstract:
We have performed a search for Bs0→μ+μ- and B0→μ+μ- decays in pp̄ collisions at s=1.96TeV using 2fb-1 of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron Collider. The observed number of Bs0 and B0 candidates is consistent with background expectations. The resulting upper limits on the branching fractions are B(Bs0→μ+μ-) <5.8×10-8 and B(B0→μ+μ-)<1.8×10-8 at 95% C.L. © 2008 The American Physical Society.Search for flavor-changing-neutral-current D meson decays
Physical Review Letters 100:10 (2008)
Abstract:
We study the flavor-changing-neutral-current process c→uμ+μ- using 1.3fb-1 of pp̄ collisions at s=1.96TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We see clear indications of the charged-current mediated Ds+ and D+→ π+→μ+μ-π+ final states with significance greater than 4 standard deviations above background for the D+ state. We search for the continuum neutral-current decay of D+→π+μ+μ- in the dimuon invariant mass spectrum away from the resonance. We see no evidence of signal above background and set a limit of B(D+→π+μ+μ-)<3.9×10-6 at the 90% C.L. This limit places the most stringent constraint on new phenomena in the c→uμ+μ- transition. © 2008 The American Physical Society.Search for flavor-changing-neutral-current d meson decays.
Phys Rev Lett 100:10 (2008) 101801
Abstract:
We study the flavor-changing-neutral-current process c-->u micro(+) micro(-) using 1.3 fb(-1) of pp[over ] collisions at square root s = 1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We see clear indications of the charged-current mediated D(s)(+) and D(+)-->phipi(+) --> micro(+)micro(-)pi(+) final states with significance greater than 4 standard deviations above background for the D(+) state. We search for the continuum neutral-current decay of D(+)-->pi(+) micro(+) micro(-) in the dimuon invariant mass spectrum away from the phi resonance. We see no evidence of signal above background and set a limit of B(D(+) --> pi(+) micro(+) micro(-))<3.9 x 10(-6) at the 90% C.L. This limit places the most stringent constraint on new phenomena in the c--> u micro(+) micro(-) transition.Limits on the production of narrow tt̄ resonances in pp̄ collisions at s=1.96TeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 77:5 (2008)
Abstract:
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.Measurement of inclusive jet cross sections in Z/γ*(→e+e-) +jets production in pp̄ collisions at s=1.96 TeV
Physical Review Letters 100:10 (2008)