Limits on extra dimensions and new particle production in the exclusive photon and missing energy signature in p anti-p collisions at s**(1/2) = 1.8-TeV

The exclusive gamma-met signal has a small standard model cross-section and is thus a good channel in which to look for signs of new physics. This signature is predicted by models with a superlight gravitino or with large extra spatial dimensions. We search for such signals at the CDF detector at the Tevatron, using 87 pb^-1 of data at sqrt(s) = 1.8 TeV, and extract 95% C.L. limits on these processes. A limit of 221 GeV is set on the scale |F|^{1/2} in supersymmetry models. For 4, 6, and 8 extra dimensions, limits on the fundamental mass scale M_D of 549, 581, and 602 GeV, respectively, are found. We also specify a `pseudo-model-independent' method of comparing the results to theoretical predictions

Measurement of the inclusive jet cross-section in anti-p p collisions at s**(1/2) = 1.8-TeV

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)

A Study of B0 ---> J / psi K(*)0 pi+ pi- decays with the collider detector at Fermilab

We report a study of the decays B0 -> J/psi K(*)0 pi+ pi-, which involve the creation of a u u-bar or d d-bar quark pair in addition to a b-bar -> c-bar(c s-bar) decay. The data sample consists of 110 1/pb of p p-bar collisions at sqrt{s} = 1.8 TeV collected by the CDF detector at the Fermilab Tevatron collider during 1992-1995. We measure the branching ratios to be BR(B0 -> J/psi K*0 pi+ pi-) = (8.0 +- 2.2 +- 1.5) * 10^{-4} and BR(B0 -> J/psi K0 pi+ pi-) = (1.1 +- 0.4 +- 0.2) * 10^{-3}. Contributions to these decays are seen from psi(2S) K(*)0, J/psi K0 rho0, J/psi K*+ pi-, and J/psi K1(1270)

Search for new heavy particles in the W Z0 final state in p anti-p collisions at s**(1/2) = 1.8-TeV

We present a search for new heavy particles, $X$, which decay via $X rightarrow WZ \to e\nu +jj$ in $p{\bar p}$ collisions at $\sqrt{s} = 1.8$ TeV. No evidence is found for production of $X$ in 110 pb$^{-1}$ of data collected by the Collider Detector at Fermilab. Limits are set at the 95% C.L. on the mass and the production of new heavy charged vector bosons which decay via $W'\to WZ$ in extended gauge models as a function of the width, $Gamma (W')$, and mixing factor between the $W'$ and the Standard Model $W$ bosons

Searches for new physics in events with a photon and b-quark jet at CDF

We have searched for evidence of physics beyond the standard model in events that include an energetic photon and an energetic b-quark jet, produced in 85pb of ppbar collisions at 1.8 TeV at the Tevatron Collider at Fermilab. This signature, containing at least one gauge boson and a third-generation quark, could arise in the production and decay of a pair of new particles, such as those predicted by Supersymmetry, leading to a production rate exceeding standard model predictions. We also search these events for anomalous production of missing transverse energy, additional jets and leptons (e, mu and tau), and additional b quarks. We find no evidence for any anomalous production of gamma-b or gamma-b+X events. We present limits on two supersymmetric models: a model where the photon is produced in the decay chi2->gamma chi1, and a model where the photon is produced in the neutralino decay into the Gravitino LSP, chi1 -> gamma G. We also present our limits in a model-independent form and test methods of applying model-independent limits

First measurement of the ratio B(t ---> W b) / B(t ---> W q) and associated limit on the CKM element |V(tb)|

We present the first measurement of the ratio of branching fraction R= B(t-->wb)/B(t-->Wq) from ppbar collisions at sqrt(s)=1.8 TeV. The data set corresponds to 109 pb-1 of data recorded by the Collider Detector at Fermilab during the 1992-1995 Tevatron run. We measure R=0.94+.31-.24 (stat+syst) or R>0.61 (0.56) at 90 (95) %C.L., in agreement with the standard model predictions. This measurement yields a limit of the Cabibbo-Kobayashi-Maskawa quark mixing matrix element Vtb under the assumption of three generation unitarity

Search for gluinos and scalar quarks in p anti-p collisions at sqrt(s) =1.8-TeV using the missing energy plus multijets signature

We have performed a search for gluinos (\gls) and squarks (\sq) in a data sample of 84 pb$^{-1}$ of \ppb collisions at $\sqrt{s}$ = 1.8 TeV, recorded by the Collider Detector at Fermilab, by investigating the final state of large missing transverse energy and 3 or more jets, a characteristic signature in R-parity-conserving supersymmetric models. The analysis has been performed `blind', in that the inspection of the signal region is made only after the predictions from Standard Model backgrounds have been calculated. Comparing the data with predictions of constrained supersymmetric models, we exclude gluino masses below 195 \gev (95% C.L.), independent of the squark mass. For the case \msq \approx \mgls, gluino masses below 300 \gev are excluded