Measurements of inclusive W and Z cross sections in pp̄ collisions at √s = 1.96 TeV
Journal of Physics G: Nuclear and Particle Physics 34:12 (2007) 2457-2544
Abstract:
We report the first measurements of inclusive W and Z boson cross-sections times the corresponding leptonic branching ratios for collisions at TeV based on the decays of the W and Z bosons into electrons and muons. The data were recorded with the CDF II detector at the Fermilab Tevatron and correspond to an integrated luminosity of 72.0 ± 4.3 pb-1. We test e-μ lepton universality in W decays by measuring the ratio of the W → μν to W → eν cross sections and determine a value of 0.991 ± 0.004(stat.) ± 0.011(syst.) for the ratio of W - ℓ - ν couplings (gμ/ge). Since there is no sign of non-universality, we combine our cross-section measurements in the different lepton decay modes and obtain σw × Br (pp̄ → W → ℓv) = 2.749 ± 0.010(stat.) ± 0.053(syst.) ± 0.165 (lum.) nb and σγ* × Br (pp̄ → γ*/Z → ℓℓ) = 254.9 ± 3.3(stat.) ± 4.6(syst.) ± 15.2(lum.) pb for dilepton pairs in the mass range between 66 GeV/c2 and 116 GeV/c2. We compute the ratio R of the W → ℓν to Z → ℓℓ cross sections taking all correlations among channels into account and obtain R = 10.84 ± 0.15(stat.) ± 0.14(syst.) including a correction for the virtual photon exchange component in our measured γ*/Z → ℓℓ cross section. Based on the measured value of R, we extract values for the W leptonic branching ratio, Br(W → ℓν)= 0.1082 ± 0.0022; the total width of the W boson, Γ(W)= 2092 ± 42 MeV; and the ratio of W and Z boson total widths, Γ(W)/Γ(Z)= 0.838 ± 0.017. In addition, we use our extracted value of Γ(W) whose value depends on various electroweak parameters and certain CKM matrix elements to constrain the Vcs CKM matrix element, |Vcs| = 0.976 ± 0.030. © 2007 IOP Publishing Ltd.The front end readout system for the T2K-ND280 detectors
IEEE Nuclear Science Symposium Conference Record 3 (2007) 1984-1991
Abstract:
The Tokai-to-Kamioka (T2K) long baseline neutrino experiment goal is to measure vμto ve oscillation parameters using near (280 m) and far (295 km) detectors from the beam origin in the J-PARC accelerator in Tokai. The far detector will be Super-Kamiokande. The 280 m near detectors complex (ND280) contain a number of scintillator based sub-detectors and a beam monitor. Approximately 54,000 scintillator bars will be read out by Multi-Pixel Photon Counter devices (MPPC) via wavelength shifting fibres. It will be the first time this novel type of photo-sensor is used on such a large scale. The front end readout system for the MPPC uses Fermilab Trip-t chips mounted on Trip-t Front end Boards (TFB). The TFB design and measured performance in conjunction with MPPC photo-sensors are presented. © 2007 IEEE.Measurement of the tt̄ production cross section in pp̄ collisions at s=1.96TeV using kinematic characteristics of lepton+jets events
Physical Review D - Particles, Fields, Gravitation and Cosmology 76:9 (2007)
Abstract:
We present a measurement of the top quark pair production cross section in pp̄ collisions at s=1.96TeV utilizing 425pb-1 of data collected with the D0 detector at the Fermilab Tevatron Collider. We consider the final state of the top quark pair containing one high-pT electron or muon and at least four jets. We exploit specific kinematic features of tt̄ events to extract the cross section. For a top quark mass of 175 GeV, we measure σtt̄=6.4-1.2+1. 3(stat)±0.7(syst)±0.4(lum)pb, in good agreement with the standard model prediction. © 2007 The American Physical Society.MiniBooNE's First Neutrino Oscillation Result
AIP Conference Proceedings AIP Publishing 957:1 (2007) 283-286
Observation of the Heavy Baryons Sigma b and Sigma b*.
Phys Rev Lett 99:20 (2007) 202001