Central pseudorapidity gaps in events with a leading antiproton at the Fermilab tevatron (p)over-barp collider

We report a measurement of the fraction of events with a large pseudorapidity gap Deltaeta within the pseudorapidity region available to the proton dissociation products X in (p) over bar +p-->(p) over bar +X. For a final state (p) over bar of fractional momentum loss xi((p) over bar) and 4-momentum transfer squared t((p) over bar) within 0.063 is found to be 0.246+/-0.001 (stat)+/-0.042 (syst) [0.184+/-0.001 (stat)+/-0.043 (syst)]. Our results are compared with gap fractions measured in minimum bias (p) over barp collisions and with theoretical expectations

Search for a W(') boson decaying to a top and bottom quark pair in 1.8 TeV p(p)over-bar collisions

We report the results of a search for a W(') boson produced in p (p) over bar collisions at a center-of-mass energy of 1.8 TeV using a 106 pb(-1) data sample recorded by the Collider Detector at Fermilab. We observe no significant excess of events above background for a W(') boson decaying to a top and bottom quark pair. In a model where this boson would mediate interactions involving a massive right-handed neutrino (nu(R)) and have standard model strength couplings, we use these data to exclude a W(') boson with mass between 225 and 536 GeV/c(2) at 95\% confidence level for M(W)(')>M(nuR) and between 225 and 566 GeV/c(2) at 95\% confidence level for M(W)(')<M(nuR)

Momentum distribution of charged particles in jets in dijet events in p(p)over-bar collisions at root s=1.8 TeV and comparisons to perturbative QCD predictions

Inclusive momentum distributions of charged particles in restricted cones around jet axes were measured in dijet events with invariant dijet masses in the range 80 to 600 GeV/c(2). Events were produced at the Fermilab Tevatron in p (p) over bar collisions with a center of mass energy of 1.8 TeV and recorded by the Collider Detector at Fermilab. The results were compared to perturbative QCD calculations carried out in the framework of the modified leading log approximation (MLLA) and assuming local parton-hadron duality. It was shown that the data follow theoretical predictions quite well over the whole range of the jet energies included in this analysis. We extracted the MLLA cutoff scale Q(eff) and found a value of 230+/-40 MeV. The theoretical prediction of E(jet)sin theta(c) scaling, where theta(c) is the cone opening angle, was experimentally observed for the first time. From the MLLA fits to the data, two more parameters were extracted: the ratio of parton multiplicities in gluon and quark jets, r=N-partons(g-jet)/N-partons(q-jet)=1.9+/-0.5, and the ratio of the number of charged hadrons to the number of predicted partons in a jet, K-LPHD(charged)=N-hadrons(charged)/N-partons=0.56+/-0.10

Search for a W(') boson decaying to a top and bottom quark pair in 1.8 TeV p(p)over-bar collisions

We report the results of a search for a W(') boson produced in p (p) over bar collisions at a center-of-mass energy of 1.8 TeV using a 106 pb(-1) data sample recorded by the Collider Detector at Fermilab. We observe no significant excess of events above background for a W(') boson decaying to a top and bottom quark pair. In a model where this boson would mediate interactions involving a massive right-handed neutrino (nu(R)) and have standard model strength couplings, we use these data to exclude a W(') boson with mass between 225 and 536 GeV/c(2) at 95% confidence level for M(W)(')>M(nuR) and between 225 and 566 GeV/c(2) at 95% confidence level for M(W)(')<M(nuR)

Search for associated production of Upsilon and vector boson in p(p)over-bar collisions at root(s)over-bar=1.8 TeV

We present a search for associated production of the Y(1S) and a vector boson in 83 pb(-1) of p (p) over bar collisions at roots=1.8 TeV collected by the CDF experiment in 1994-1995. We find no evidence of the searched signal in the data, and set upper limits to the production cross sections