The cross section for the production and subsequent decay to electron and neutrino of the W intermediate vector boson has been measured in 1.8-TeV p¯p collisions at the Fermilab Tevatron Collider. An analysis of events with missing transverse energy greater than 25 GeV and with an electron of transverse energy greater than 15 GeV from a datum sample of 25.3 nb−1 gives σB=2.6±0.6±0.5 nb.

An analysis of high-transverse-momentum electrons using data from the Collider Detector at Fermilab (CDF) of p¯p collisions at s=1800 GeV yields values of the production cross section times branching ratio for W and Z0 bosons of σ(p¯p→WX→eνX)=2.19±0.04(stat)±0.21(syst) nb and σ(p¯p→Z0X→e+e−X)=0.209±0.013(stat)±0.017(syst) nb. Detailed descriptions of the CDF electron identification, background, efficiency, and acceptance are included. Theoretical predictions of the cross sections that include a mass for the top quark larger than the W mass, current values of the W and Z0 masses, and higher-order QCD corrections are in good agreement with these measured values.

This letter reports the full reconstruction of B mesons through the decay chain B±→J/ψ K±, J/ψ→μ+μ−, using data obtained at the Collider Detector at Fermilab in p¯p collisions at √s =1.8 TeV. This exclusive sample, the first observed at a hadron collider, is then used to measure the B-meson cross section, from which we extract the b-quark cross section. We obtain σ=2.8±0.9 (stat) ±1.1(syst) μb for B− mesons with PT>9.0 GeV/c and rapidity ‖y‖<1.0. We obtain σ=6.1±1.9(stat) ±2.4(syst) μb, for b quarks with transverse momentum PT>11.5 GeV/c and rapidity ‖y‖<1.0.

An analysis of proton-antiproton collisions at √s =1.8 TeV recorded with the Collider Detector at Fermilab (CDF) yields σ(pp¯→WX)B(W→μν)=2.21±0.22 nb and σ(pp¯→ZX)B(Z →μ+μ−)=0.226±0.032 nb. The ratio is Rμ=σWB(W→μν)/σZB(Z→μ+μ−)=9.8±1.2. Combining with previous CDF electron results gives σWB(W→lν)=2.20±0.20 nb, σZB(Z→l+l−)=0.214±0.023 nb, and Rl=10.0±0.8. We extract the ratios of the coupling constants gμ/ge and gτ/gμ. Using standard model assumptions we deduce the inverse branching ratio B−1(W→lν), the width Γ(W), and a decay-mode-independent lower bound on the top quark mass of 45 GeV/c2 (95% C.L.).

We present an analysis of data from p p¯ collisions at a center-of-mass energy of √s =1800 GeV. A measurement is made of the ratio R≡σB(p p¯→W→eν)/σB(p p¯→Z0→ee). The data represent 19.6 pg−1 collected by the Collider Detector at Fermilab during the 1992–1993 collider run of the Fermilab Tevatron. We find R=10.90±0.32(stat)±0.29(syst), and from this value we extract a measurement of the W→eν branching ratio Γ(W→eν)/Γ(W)=0.1094±0.0033(stat)±0.0031(syst). From this branching ratio we set a limit on the top quark mass of mt>62 GeV/c2 at the 95% confidence level. In contrast with direct searches for the top quark, this limit makes no assumptions about the allowed decay modes of the top quark. In addition, we use a calculation of the leptonic width Γ(W→eν) to obtain a value for the W total decay width: Γ(W)=2.064±0.060(stat)±0.059(syst) GeV.

This paper reports a measurement of the cross section for the pair production of top quarks in ppbar collisions at sqrt(s) = 1.96 TeV at the Fermilab Tevatron. The data was collected from the CDF II detector in a set of runs with a total integrated luminosity of 1.1 fb^{-1}. The cross section is measured in the dilepton channel, the subset of ttbar events in which both top quarks decay through t -> Wb -> l nu b where l = e, mu, or tau. The lepton pair is reconstructed as one identified electron or muon and one isolated track. The use of an isolated track to identify the second lepton increases the ttbar acceptance, particularly for the case in which one W decays as W -> tau nu. The purity of the sample may be further improved at the cost of a reduction in the number of signal events, by requiring an identified b-jet. We present the results of measurements performed with and without the request of an identified b-jet. The former is the first published CDF result for which a b-jet requirement is added to the dilepton selection. In the CDF data there are 129 pretag lepton + track candidate events, of which 69 are tagged. With the tagging information, the sample is divided into tagged and untagged sub-samples, and a combined cross section is calculated by maximizing a likelihood. The result is sigma_{ttbar} = 9.6 +/- 1.2 (stat.) -0.5 +0.6 (sys.) +/- 0.6 (lum.) pb, assuming a branching ratio of BR(W -> ell nu) = 10.8% and a top mass of m_t = 175 GeV/c^2.

The cross section for photon production in association with at least one jet containing a $b$-quark hadron has been measured in proton antiproton collisions at $\sqrt{s}=1.96$ TeV. The analysis uses a data sample corresponding to an integrated luminosity of 340 pb$^{-1}$ collected with the CDF II detector. Both the differential cross section as a function of photon transverse energy $E_T^{\gamma}$, $d \sigma$($p \overline{p} \to \gamma + \geq 1 b$-jet)/$d E_T^{\gamma}$ and the total cross section $\sigma$($p \overline{p} \to \gamma + \geq 1 b$-jet/ $E_T^{\gamma}> 20$ GeV) are measured. Comparisons to a next-to-leading order prediction of the process are presented.

We report on measurements of the branching ratios of the decays B+→χc10(1P)K+ and B+→J/ψK+π+π−, where χc10(1P)→J/ψγ and J/ψ→μ+μ− in pp¯ collisions at s=1.8TeV. Using a data sample from an integrated luminosity of 110pb−1 collected by the Collider Detector at Fermilab we measure the branching ratios to be BR(B+→χc10(1P)K+)=15.5±5.4(stat)±1.5(syst)±1.3(br)×10−4 and BR(B+→J/ψK+π+π−)=6.9±1.8(stat)±1.1(syst)±0.4(br)×10−4 where (br) is due to the finite precision on BR(B+→J/ψK+), BR(χc10(1P)→J/ψγ) is used to normalize the signal yield, and (syst) encompasses all other systematic uncertainties.

We present a measurement of the cross section and the first measurement of the heavy flavor content of associated direct photon + muon events produced in hadronic collisions. These measurements come from a sample of 1.8 TeV ppbar collisions recorded with the Collider Detector at Fermilab. Quantum chromodynamics (QCD) predicts that these events are primarily due to Compton scattering process charm+gluon -> charm+photon, with the final state charm quark producing a muon. The cross section for events with a photon transverse momentum between 12 and 40 GeV/c is measured to be 46.8+-6.3+-7.5 pb, which is two standard deviations below the most recent theoretical prediction. A significant fraction of the events in the sample contain a final-state bottom quark. The ratio of charm to bottom production is measured to be 2.4+-1.2, in good agreement with QCD models.

We present results from a measurement of double diffraction dissociation in $\bar pp$ collisions at the Fermilab Tevatron collider. The production cross section for events with a central pseudorapidity gap of width $\Delta\eta^0>3$ (overlapping $\eta=0$) is found to be $4.43\pm 0.02{(stat)}{\pm 1.18}{(syst) mb}$ [$3.42\pm 0.01{(stat)}{\pm 1.09}{(syst) mb}$] at $\sqrt{s}=1800$ [630] GeV. Our results are compared with previous measurements and with predictions based on Regge theory and factorization.