Inclusive jet cross sections have been measured in p¯p collisions at √s =546 and 1800 GeV, using the Collider Detector at Fermilab. The ratio of jet cross sections is compared to predictions from simple scaling and O(as3) QCD. Our data exclude scaling and lie (1.5–2.4)σ below a range of QCD predictions.
We have measured the ratio of prompt production rates of the charmonium states χc1 and χc2 in 110pb−1 of pp¯ collisions at s=1.8TeV. The photon from their decay into J/ψγ is reconstructed through conversion into e+e− pairs. The energy resolution this technique provides makes the resolution of the two states possible. We find the ratio of production cross sections σχc2σχc1=0.96±0.27(stat)±0.11(syst) for events with pT(J/ψ)>4.0GeV/c, |η(J/ψ)|<0.6, and pT(γ)>1.0GeV/c.
We present a search for first generation leptoquark with 110pb^1 of data collected with the CDF detector. We set 95% C.L. cross section limits as a function of the leptoquark mass.
We have measured the cross section of γ+D*± production in p¯p collisions at s=1.8TeV using the Collider Detector at Fermilab. In this kinematic region, the Compton scattering process (gc→γc) is expected to dominate and thus provide a direct link to the charm quark density in the proton. From the 45±18 γ+D*± candidates in a 16.4pb−1 data sample, we have determined the production cross section to be 0.38±0.15(stat)±0.11(syst) nb for the rapidity range |y(D*±)|<1.2 and |y(γ)|<0.9, and for the transverse momentum range pT(D*±)>6GeV/c and 16<pT(γ)<40GeV/c. The measured cross section is compared to a theoretical prediction.
We have used 19 pb**-1 of data collected with the Collider Detector at Fermilab to search for new particles decaying to dijets. We exclude at 95% confidence level models containing the following new particles: axigluons with mass between 200 and 870 GeV, excited quarks with mass between 80 and 570 GeV, and color octet technirhos with mass between 320 and 480 GeV.
We report on a study of W+ photon production in approximately 20 pb−1 of p−p¯ collisions at s=1.8 TeV recorded with the Collider Detector at Fermilab. Our results are in good agreement with standard model expectations and are used to obtain limits on anomalous CP-conserving WWγ couplings of −2.3<Δκ<2.2 for λ=0 and −0.7<λ<0.7 for Δκ=0 at 95% C.L. We obtain the same limits for CP-violating couplings. These results provide limits on the higher-order electromagnetic moments of the W boson of 0.8<gW<3.1 for qWe=1 and −0.6<qWe<2.7 for gW=2 at 95% C.L.
We present results from the measurement of the inclusive jet cross section for jet transverse energies from 40 to 465 GeV in the pseudo-rapidity range $0.1<|\eta|<0.7$. The results are based on 87 $pb^{-1}$ of data collected by the CDF collaboration at the Fermilab Tevatron Collider. The data are consistent with previously published results. The data are also consistent with QCD predictions given the flexibility allowed from current knowledge of the proton parton distributions. We develop a new procedure for ranking the agreement of the parton distributions with data and find that the data are best described by QCD predictions using the parton distribution functions which have a large gluon contribution at high $E_T$ (CTEQ4HJ).
We present a study of pp¯ collisions at s=1800 and 630 GeV collected using a minimum bias trigger by the CDF experiment in which the data set is divided into two classes corresponding to “soft” and “hard” interactions. For each subsample, the analysis includes measurements of the multiplicity, transverse momentum (pT) spectrum, and the average pT and event-by-event pT dispersion as a function of multiplicity. A comparison of results shows distinct differences in the behavior of the two samples as a function of the center of mass (c.m.) energy. We find evidence that the properties of the soft sample are invariant as a function of c.m. energy.
We present a measurement of the cross section for production of isolated prompt photons in p¯p collisions at √s =1.8 TeV. The cross section, measured as a function of transverse momentum (PT), agrees qualitatively with QCD calculations but has a steeper slope at low PT.
The W production cross section times the branching ratio for W→lν, l=e,μ decays has been measured as a function of the associated jet multiplicity. The data have been recorded at the Collider Detector at Fermilab during the 1988–89 run. A recent leading order QCD calculation agrees well with the data up to a jet multiplicity of 4.
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