Search for the Higgs Boson Produced in Association with Z→ℓ+ℓ- in pp̄ Collisions at s=1.96TeV
Physical Review Letters 101:25 (2008)
Abstract:
We present a search for the Higgs boson in the process qq̄→ ZH→ℓ+ℓ-bb̄. The analysis uses an integrated luminosity of 1fb-1 of pp̄ collisions produced at s=1.96TeV and accumulated by the upgraded Collider Detector at Fermilab (CDF II). We employ artificial neural networks both to correct jets mismeasured in the calorimeter and to distinguish the signal kinematic distributions from those of the background. We see no evidence for Higgs boson production, and set 95% C.L. upper limits on σZHB(H→bb̄), ranging from 1.5 to 1.2 pb for a Higgs boson mass (mH) of 110 to 150GeV/c2. © 2008 The American Physical Society.First measurement of the fraction of top-quark pair production through gluon-gluon fusion
Physical Review D - Particles, Fields, Gravitation and Cosmology 78:11 (2008)
Abstract:
We present the first measurement of σ(gg→tt̄)/ σ(pp̄→tt̄). We use 0.96fb-1 of s=1.96TeV pp̄ collision data recorded with the CDF II detector at Fermilab. Using charged particles with low transverse momentum in tt̄ events, we find σ(gg→ tt̄)/σ(pp̄→tt̄)=0.07±0.14(stat)±0. 07(syst), corresponding to a 95% confidence level upper limit of 0.33, in agreement with the standard model next-to-leading-order prediction of 0.15±0.05. © 2008 The American Physical Society.Two-photon widths of the χcJ states of charmonium
Physical Review D - Particles, Fields, Gravitation and Cosmology 78:9 (2008)
Abstract:
Using a data sample of 24.5×106 ψ(2S) the reactions ψ(2S)→γχcJ, χcJ→γγ have been studied for the first time to determine the two-photon widths of the χcJ states of charmonium in their decay into two photons. The measured quantities are B(ψ(2S)→γχc0)×B(χc0→γγ)=(2. 17±0.32±0.10)×10-5 and B(ψ(2S)→γχc2) ×B(χc2→γγ)=(2.68±0.28±0.15)×10-5. Using values for B(ψ(2S)→γχc0,c2) and Γ(χc0,c2) from the literature the two-photon widths are derived to be Γγ γ(χc0)=(2.36±0.35±0.22)keV, Γγγ(χ c2)=(0.66±0.07±0.06)keV, and R≡Γγγ(χ c2)/Γγγ(χc0)=0.278±0.050±0.036. The importance of the measurement of R is emphasized. For the forbidden transition, χc1→γγ, an upper limit of Γγγ(χc1) <0.03keV is established. © 2008 The American Physical Society.Measurement of the kT Distribution of Particles in Jets Produced in ppbar Collisions at s**(1/2)=1.96$-TeV
ArXiv 0811.2820 (2008)
Inclusive Search for Squark and Gluino Production in ppbar Collisions at sqrt{s} = 1.96 TeV
ArXiv 0811.2512 (2008)