[en] Inclusive jet cross section and di-jet angular distribution results from the CDF and D0 collaborations are presented. The possibility that compositeness might be evident at high transverse energies is explored by both experiments. Using the angular distributions, the CDF analysis excludes at the 95% CL regions with Λ⁺ ≤ 1.8 TeV and Λ^- ≤ 1.6 TeV for a model where all quarks are allowed to be composite objects. The D0 preliminary result excludes at the 95% CL regions with Λ⁺ ≤ 2.0 TeV for the same model. (author)

[en] Inclusive jet cross section and dijet angular distribution results from the CDF and D0 collaborations are presented. The possibility that compositeness might be evident at high transverse energies is explored by both experiments. Using the angular distributions, the CDF analysis excludes at the 95% CL regions with Λ⁺ < 1.8 TeV and Λ^- < 1.6 TeV for a model where all quarks are allowed to be composite objects. The D0 preliminary result excludes at the 95% CL regions with Λ⁺ < 2.0 TeV for the same model

[en] We present several results on high P_T jet production and compare them to the most recent theoretical predictions using the latest parton distribution functions. The dijet invariant mass distribution, triple differential cross section, and dijet angular distribution measurements exhibit very good agreement with the theoretical predictions. The latter agreement obviates the need to invoke compositeness models. At √ (s) =630thinspGeV, the inclusive jet cross section lies 15 endash 20% below the theoretical predictions for both experiments. At √ (s) =1800thinspGeV, the DO/ inclusive jet cross section is in agreement with the theoretical predictions over the entire jet E_T range, the CDF collaboration observes an excess in the cross section for E_T above 200 GeV. copyright 1998 American Institute of Physics

[en] Large samples of data with jets at high pseudorapidities have been collected at the Fermilab Tevatron p bar p collider at √s=1.8 TeV. Both the DO/ and CDF experiments have used the dijet cross sections, d³σ/dE_Tdη₁dη₂, to make detailed tests of perturbative QCD. These data sets will eventually place constraints on the gluon distribution functions. Results presented here are from data taken during 1992 endash 1993. copyright 1996 American Institute of Physics

[en] The D OE detector has completed its first data taking run at the Fermi National Accelerator Laboratory's bar p-p Tevatron collider. The Level 0 trigger system is the D OE experiment's first trigger level used to identify colliding beam crossings containing interactions. It consists of two hodoscopes of scintillation tiles located just outside the D OE central tracking region. The Level 0 trigger provides a fast measurement of the interaction position along the beam axis for use in early trigger decisions. A slower, more accurate position of the interaction and an indication of the occurrence of multiple interactions are available for subsequent trigger decisions. In addition, the Level 0 trigger is used as a luminosity monitor for D OE. Results on the performance of the Level 0 trigger are presented

[en] We have made a precise measurement of the central inclusive jet cross section at √ (s) =1.8 TeV . The measurement is based on an integrated luminosity of 92 pb^-1 collected at the Fermilab Tevatron p p Collider with the D0 detector. The cross section, reported as a function of jet transverse energy (E_T ≥ 60 GeV ) in the pseudorapidity interval | η | ≤ 0.5, is in good agreement with predictions from next-to-leading order quantum chromodynamics. copyright 1999 The American Physical Society

[en] We report on a search for pair production of a fourth generation charge -1/3 quark (b^') in pp collisions at √(s)=1.8TeV by the DO/ experiment at the Fermilab Tevatron using an integrated luminosity of 93pb^-1. Both b^' quarks are assumed to decay via flavor changing neutral currents (FCNC). The search uses the signatures γ+3 jets +μ-tag and 2γ+2 jets. We see no significant excess of events over the expected background. We place an upper limit on the production cross section times branching fraction that is well below theoretical expectations for a b^' decaying exclusively via FCNC for b^' masses up to m_Z+m_b. copyright 1997 The American Physical Society

[en] We report a measurement of the W boson mass based on an integrated luminosity of 82 pb^-1 from p bar p collisions at √(s)=1.8 TeV recorded in 1994 endash 1995 by the D0 detector at the Fermilab Tevatron. We identify W bosons by their decays to eν and extract the mass by fitting the transverse mass spectrum from 28323W boson candidates. A sample of 3563dielectron events, mostly due to Z→ee decays, constrains models of W boson production and the detector. We measure M_W=80.44±0.10(stat)± 0.07(syst) GeV . By combining this measurement with our result form the 1992 endash 1993 data set, we obtain M_W=80.43±0.11 GeV . copyright 1998 The American Physical Society

[en] We present a study of Zγ+X production in p bar p collisions at √ (s) =1.8TeV from 97 (87)pb^-1 of data collected in the eeγ (μmuγ) decay channel with the D0 detector at Fermilab. The event yield and kinematic characteristics are consistent with the standard model predictions. We obtain limits on anomalous ZZγ and Zγγ couplings for form factor scales Λ=500GeV and Λ=750GeV. Combining this analysis with our previous results yields 95% C.L. limits [h₃₀^Z]<0.36, [h₄₀^Z]<0.05, [h₃₀^γ]<0.37, and [h₄₀^γ]<0.05 for a form factor scale Λ=750GeV. copyright 1998 The American Physical Society

[en] We have searched for the pair production of first generation scalar leptoquarks in the eejj channel using the full data set (123 pb^-1) collected with the D0 detector at the Fermilab Tevatron during 1992 endash 1996. We observe no candidates with an expected background of approximately 0.4 events. Comparing the experimental 95% confidence level upper limit to theoretical calculations of the cross section with the assumption of a 100% branching fraction of eq, we set a lower limit on the mass of a first generation scalar leptoquark of 225 GeV/c². The results of this analysis rule out the interpretation of the excess of high Q² events at DESY HERA as leptoquarks which decay exclusively to eq. copyright 1997 The American Physical Society