Publisher's Note: Search for hadronic decays of W and Z bosons in photon events in pp̄ collisions at s=1.96TeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 80:7 (2009)
Measurements of the top-quark mass using charged particle tracking
ArXiv 0910.0969 (2009)
Observation of the Ωb- baryon and measurement of the properties of the Ξb- and Ωb- baryons
Physical Review D - Particles, Fields, Gravitation and Cosmology 80:7 (2009)
Abstract:
We report the observation of the bottom, doubly-strange baryon Ωb- through the decay chain Ωb-→J/ψΩ-, where J/ψ→μ+μ-, Ω-→ΛK-, and Λ→pπ-, using 4.2fb-1 of data from pp̄ collisions at s=1.96TeV, and recorded with the Collider Detector at Fermilab. A signal is observed whose probability of arising from a background fluctuation is 4.0×10-8, or 5.5 Gaussian standard deviations. The Ωb- mass is measured to be 6054.4±6. 8(stat)±0.9(syst)MeV/c2. The lifetime of the Ωb- baryon is measured to be 1.13-0.40+0.53(stat)±0.02(syst)ps. In addition, for the Ξb- baryon we measure a mass of 5790.9±2.6(stat)±0.8(syst)MeV/c2 and a lifetime of 1.56-0.25+0.27(stat)±0.02(syst)ps. Under the assumption that the Ξb- and Ωb- are produced with similar kinematic distributions to the Λb0 baryon, we find σ(Ξb-)B(Ξb-→J/ψΞ-) σ(Λb0)B(Λb0→J/ψΛ)=0.167-0.025+0.037(stat) ±0.012(syst) and σ(Ωb-)B(Ωb-→J/ψΩ-) σ(Λb0)B(Λb0→J/ψΛ)=0.045-0.012+0.017(stat) ±0.004(syst) for baryons produced with transverse momentum in the range of 6-20GeV/c. © 2009 The American Physical Society.Inclusive radiative ψ(2S) decays
Physical Review D - Particles, Fields, Gravitation and Cosmology 80:7 (2009)
Abstract:
Using e+e- collision data taken with the CLEO-c detector at the Cornell Electron Storage Ring, we have investigated the direct photon spectrum in the decay ψ(2S)→γgg. We determine the ratio of the inclusive direct photon decay rate to that of the dominant three-gluon decay rate ψ(2S)→ggg (Rγ≡⌈Γgg(γgg)/⌈(ggg)) to be Rγ(zγ>0.4)=0.070±0.002±0.019±0.011, with zγ defined as the scaled photon energy relative to the beam energy. The errors shown are statistical, systematic, and that due to the uncertainty in the input branching fractions used to extract the ratio, respectively. © 2009 The American Physical Society.Precision measurement of the X(3872) mass in J/ψπ+π- decays
Physical Review Letters 103:15 (2009)