[en] An analysis is presented of events with a single jet and significant missing transverse energy selected from 4.7 pb^-1 of data collected at the Fermilab Tevatron with the CDF detector. The goal is to identify events of the type p bar p → Z⁰ + jet; Z⁰ → ν bar ν. Event selection and backgrounds are discussed. The number of observed monojet events is compared to the number of observed Z⁰ → e^+- events in which the Z⁰ is accompanied by a jet. We measure the number of light neutrino species to be N_ν = 2.2±1.5 and we place an upper limit on the number of neutrino species at N_ν < 5 (90% C.L.)

[en] The latest results of searches at D0 for physics beyond the Standard Model are presented. These include searches for new weak vector bosons, second generation leptoquarks, a bosonic Higgs, SUSY particles (squarks, gluinos, winos, zinos, and a light stop squark), and a fourth generation heavy neutrino. For each search, backgrounds and physics signals are discussed. No evidence for new physics has been observed. Limits on cross sections and masses are presented

[en] An analysis is presented of events with a single jet and significant missing transverse energy selected from 4.7 pb^-1 of p bar p data at √s = 1800 GeV. The goal is to identify events of the type p bar p → Z⁰ + jet; Z⁰ → ν bar ν. Event selection backgrounds are discussed. The number of observed monojet events is compared to the number of observed Z⁰ → e⁺e^- events in which the Z⁰ is accompanied by a jet. We measure the number of light neutrino species to be N_v = 2.2 ± 1.5 and we place an upper limit on the cross section for new physics of 8.3 pb (95% C.L.)

[en] The muon spectrometer for the D0 experiment at Fermi National Accelerator Laboratory uses proportional drift tubes filled with an Ar-CO₂-CF₄ gas mixture. Measurements of drift velocity as a function of electric field magnitude for 90%-5%-5% and 90%-4%-6% Ar-CO₂-CF₄ mixtures are presented, and our operational experiences with these gases at D0 is discussed

[en] The level 2 muon trigger for the upgraded D0 detector is based on finding either a track segment directly outside the calorimeter or a full track that includes hits on either side of the magnetized iron toroid. The architecture for level 2 includes the use of a preprocessor which will be used to find the segments. Queueing simulation of the level 2 architecture shows a strong dependence between deadtime and large events in the preprocessors when a serial computation is performed. By using a parallel preprocessor architecture where each individual processor focuses on a narrow path through the detector, the effect of large events or slow calculations on deadtime is eliminated. The CNAPS commercial parallel processor board is considered for the muon preprocessor. (orig.)

[en] We describe the design, construction, and operating experience of unique drift chambers with radially strung wires for the Collider Detector of Fermilab (CDF) which cover forward and backward cone angles between 2⁰ and 10⁰, and 170⁰ and 178⁰. The chambers are capable of operating in our high rate and high track multiplicity environment with excellent multitrack resolution of 2-3 mm and high tracking accuracy of 140 μm per wire. Results from the recent running experience will be presented. (orig.)

[en] The W' is a charged, heavy, vector boson predicted to exist by some extensions of the standard model. We have searched for the processes W'→eν and W'→μν for M_W'>100 GeV/c², in bar pp collisions at √s =1.8 TeV, using data taken with the Collider Detector at Fermilab. The nonobservation of these processes leads to a lower limit of 520 Gev/c² (95% confidence level) on the mass of the W', assuming standard-strength couplings to three fermion generations

[en] During the 1988/1989 run at the Fermilab Tevatron, the CDF detector collected ≅ 4.1 pb^-1 of p bar p data at √s = 1.8 TeV. The main goals of this run being physics at high p_t, the CDF trigger was tuned for maximizing signals from Z⁰s, Ws, t-quarks, and etc. As such, compared to the high pt physics, the b-physics program was of secondary importance other than that which would be used for background calculations. Also, CDF had no vertex chamber capability for seeing displaced vertices. However, significant b-quark physics results are evident in two data samples: (1) inclusive electrons; (2) inclusive J/ψ where J/ψ → μ⁺μ^-. In this paper, the author will try to specify the goals for b-physics using the inclusive electrons and J/ψ signals for the 1988/89 data set. He will then provide a brief look at the data, and will finish with some highly speculative guesses as to whether or not experiments at the Tevatron which look for CP violation in the b sector are possible

[en] We present the dijet invariant-mass distribution in the region between 60 and 500 GeV, measured in 1.8-TeV bar pp collisions in the Collider Detector at Fermilab. Jets are restricted to the pseudorapidity interval |η|<0.7. Data are compared with QCD calculations; axigluons are excluded with 95% confidence in the region 120< M_A<210 GeV for axigluon width Γ_A=Nα_sM_A/6, with N=5

[en] We have measured the Z-boson production differential cross section as a function of transverse momentum using Z→ee and Z→μμ decays in bar pp collision at √s =1.8 TeV with the Collider Detector at Fermilab. Comparison with standard-model predictions shows good agreement over the range 0< p_T<160 GeV/c available from this data sample