Search for resonant tt[overline] production in pp[overline] collisions at sqrt[s]=1.96 TeV

We report on a search for narrow-width particles decaying to a top and antitop quark pair. The data set used in the analysis corresponds to an integrated luminosity of 680 pb(-1) collected with the Collider Detector at Fermilab in run II. We present 95% confidence level upper limits on the cross section times branching ratio. Assuming a specific top-color-assisted technicolor production model, the leptophobic Z' with width Gamma(Z')=0.012M(Z'), we exclude the mass range M(Z')<725 GeV/c(2) at the 95% confidence level.

Search for the Higgs boson in events with missing transverse energy and b quark jets produced in pp collisions at square root(s)=1.96 TeV

We search for the standard model Higgs boson produced in association with an electroweak vector boson in events with no identified charged leptons, large imbalance in transverse momentum, and two jets where at least one contains a secondary vertex consistent with the decay of b hadrons. We use approximately 1 fb(-1) integrated luminosity of pp collisions at square root(s)=1.96 TeV recorded by the Collider Detector at Fermilab II experiment at the Tevatron. We find 268 (16) single (double) b-tagged candidate events, where 248+/-43 (14.4+/-2.7) are expected from standard model background processes. We observe no significant excess over the expected background and thus set 95% confidence level upper limits on the Higgs boson production cross section for several Higgs boson masses ranging from 110 to 140 GeV/c(2). For a mass of 115 GeV/c(2), the observed (expected) limit is 20.4 (14.2) times the standard model prediction.

Underwater digital holography for studies of marine plankton

Conventional and digital holographies are proving to be increasingly important for studies of marine zooplankton and other underwater biological applications. This paper reports on the use of a subsea digital holographic camera (eHoloCam) for the analysis and identification of marine organisms and other subsea particles. Unlike recording on a photographic film, a digital hologram (e-hologram) is recorded on an electronic sensor and reconstructed numerically in a computer by simulating the propagation of the optical field in space. By comparison with other imaging techniques, an e-hologram has several advantages such as three-dimensional spatial reconstruction, non-intrusive and non-destructive interrogation of the recording sampling volume and the ability to record holographic videos. The basis of much work in optics lies in Maxwell's electromagnetic theory and holography is no exception: we report here on two of the numerical reconstruction algorithms we have used to reconstruct holograms obtained using eHoloCam and how their starting point lies in Maxwell's equations. Derivation of the angular spectrum algorithm for plane waves is provided as an exact method for the in-line numerical reconstruction of digital holograms. The Fresnel numerical reconstruction algorithm is derived from the angular spectrum method. In-line holograms are numerically processed before and after reconstruction to remove periodic noise from captured images and to increase image contrast. The ability of the Fresnel integration reconstruction algorithm to extend the reconstructed volume beyond the recording sensor dimensions is also shown with a 50% extension of the reconstruction area. Finally, we present some images obtained from recent deployments of eHoloCam in the North Sea and Faeroes Channel.

Strong evidence for ZZ production in pp[over] collisions at sqrt[s]=1.96 TeV

We report the first evidence of Z boson pair production at a hadron collider with a significance exceeding 4 standard deviations. This result is based on a data sample corresponding to 1.9 fb(-1) of integrated luminosity from pp[over] collisions at sqrt[s]=1.96 TeV collected with the Collider Detector at Fermilab II detector. In the lll'l' channel, we observe three ZZ candidates with an expected background of 0.096(-0.063)+0.092 events. In the llnunu channel, we use a leading-order calculation of the relative ZZ and WW event probabilities to discriminate between signal and background. In the combination of lll'l' and llnunu channels, we observe an excess of events with a probability of 5.1 x 10(-6) to be due to the expected background. This corresponds to a significance of 4.4 standard deviations. The measured cross section is sigma(pp[over]-->ZZ)=1.4(-0.6)+0.7(stat+syst) pb, consistent with the standard model expectation.

Observation of the decay Bc+/--->J/psipi+/- and measurement of the Bc+/- mass

The Bc+/- meson is observed through the decay Bc+/--->J/psipi+/-, in data corresponding to an integrated luminosity of 2.4 fb(-1) recorded by the Collider Detector at Fermilab II detector at the Fermilab Tevatron. A signal of 108+/-15 candidates is observed, with a significance that exceeds 8sigma. The mass of the Bc+/- meson is measured to be 6275.6+/-2.9(stat)+/-2.5(syst) MeV/c2.

First flavor-tagged determination of bounds on mixing-induced CP violation in Bs0 --> J/psiphi decays

This Letter describes the first determination of bounds on the CP-violation parameter 2beta(s) using B(s)(0) decays in which the flavor of the bottom meson at production is identified. The result is based on approximately 2000 B(s)(0)-->J/psiphi decays reconstructed in a 1.35 fb(-1) data sample collected with the CDF II detector using pp collisions produced at the Fermilab Tevatron. We report confidence regions in the two-dimensional space of 2beta(s) and the decay-width difference DeltaGamma. Assuming the standard model predictions of 2beta(s) and DeltaGamma, the probability of a deviation as large as the level of the observed data is 15%, corresponding to 1.5 Gaussian standard deviations.

Search for heavy toplike quarks using lepton plus jets events in 1.96 TeV pp collisions

We present the results of a search for pair production of a new heavy toplike quark t' decaying to a W boson and another quark using the Collider Detector at Fermilab II detector in run II of the Tevatron pp collider. Using a data sample corresponding to 760 pb(-1) of integrated luminosity, we fit the observed spectrum of total transverse energy and reconstructed t' quark mass to a combination of standard model processes and t' pair production. We see no evidence for t't' production, and we infer a lower limit of 256 GeV/c(2) on the mass of the t' at 95% C.L. assuming standard strong couplings for the t'.

Measurement of Lifetime and Decay-Width Difference in B_{s};{0}-->J/psivarphi Decays

We measure the mean lifetime tau=2/(Gamma_{L}+Gamma_{H}) and the decay-width difference DeltaGamma=Gamma_{L}-Gamma_{H} of the light and heavy mass eigenstates of the B_{s}{0} meson, B_{sL}{0} and B_{sH}{0}, in B_{s}{0}-->J/psivarphi decays using 1.7 fb;{-1} of data collected with the CDF II detector at the Fermilab Tevatron pp[over ] collider. Assuming CP conservation, a good approximation for the B_{s}{0} system in the standard model, we obtain DeltaGamma=0.076_{-0.063}{+0.059}(stat)+/-0.006(syst) ps{-1} and tau=1.52+/-0.04(stat)+/-0.02(syst) ps, the most precise measurements to date. Our constraints on the weak phase and DeltaGamma are consistent with CP conservation.

Evidence for D0-D(0) mixing using the CDF II detector

We measure the time dependence of the ratio of decay rates for the rare decay D{0}-->K{+}pi{-} to the Cabibbo-favored decay D{0}-->K{-}pi;{+}. A signal of 12.7x10;{3} D{0}-->K{+}pi{-} decays was obtained using the Collider Detector at Fermilab II detector at the Fermilab Tevatron with an integrated luminosity of 1.5 fb;{-1}. We measure the D0-D[over ]{0} mixing parameters (R_{D},y{'},x{'2}), and find that the data are inconsistent with the no-mixing hypothesis with a probability equivalent to 3.8 Gaussian standard deviations.

Search for Bs0 --> micro+ micro- and B0 --> micro+ micro- decays with 2 fb-1 of pp collisions

We have performed a search for B(s)(0) --> micro(+) micro(-) and B(0) --> micro(+) micro(-) decays in pp collisions at square root s = 1.96 TeV using 2 fb(-1) of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron Collider. The observed number of B(s)(0) and B0 candidates is consistent with background expectations. The resulting upper limits on the branching fractions are B(B(s)0) --> micro(+) micro(-)) <5.8 x 10(-8) and B(B(0) --> micro(+) micro(-))<1.8 x 10(-8) at 95% C.L.

Measurement of inclusive jet cross sections in Z/gamma*(-->e+e-) + jets production in pp[over ] collisions at square root s = 1.96 TeV

Inclusive jet cross sections in Z/gamma* events, with Z/gamma* decaying into an electron-positron pair, are measured as a function of jet transverse momentum and jet multiplicity in pp[over ] collisions at square root s = 1.96 TeV with the upgraded Collider Detector at Fermilab in run II, based on an integrated luminosity of 1.7 fb(-1). The measurements cover the rapidity region |y(jet)|<2.1 and the transverse momentum range p(T)(jet)>30 GeV/c. Next-to-leading order perturbative QCD predictions are in good agreement with the measured cross sections.

First measurement of W boson production in association with a single Charm quark in pp collisions at sqrt(s)=1.96 TeV

We present the first measurement of the production cross section of a W boson with a single charm quark (c) in pp collisions at sqrt(s)=1.96 TeV, using soft muon tagging of c jets. In a data sample of approximately 1.8 fb(-1), recorded with the Collider Detector at Fermilab II detector at the Fermilab Tevatron, we select events with W+1 or 2 jets. We use the charge correlation between the W and the muon from the semileptonic decay of a charm hadron to extract the Wc signal. We measure sigma Wc(PTc >20 GeV/c,|eta c|<1.5) x BR(W-->l nu)=9.8+/-3.2 pb, in agreement with theoretical expectations.

Observation of orbitally excited B(s) mesons

We report the observation of two narrow resonances consistent with states of orbitally excited (L=1) B_(s) mesons using 1 fb;(-1) of pp[over ] collisions at sqrt[s]=1.96 TeV collected with the Collider Detector at Fermilab II detector at the Fermilab Tevatron. We use two-body decays into K- and B+ mesons reconstructed as B(+)-->J/psiK(+), J/psi-->mu(+)mu(-) or B(+)-->D[over ](0)pi(+), D[over ](0)-->K(+)pi(-). We deduce the masses of the two states to be m(B_(s1))=5829.4+/-0.7 MeV/c(2) and m(B_(s2);(*))=5839.6+/-0.7 MeV/c;(2).

Direct measurement of the W Boson width in ppover collisions at square roots = 1.96 TeV

A direct measurement of the total decay width of the W boson Gamma(W) is presented using 350 pb(-1) of data from pp[over ] collisions at square root s = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. The width is determined by normalizing predicted signal and background distributions to 230 185 W candidates decaying to enu and micronu in the transverse-mass region 50<M(T)<90 GeV and then fitting the predicted shape to 6055 events in the high-M(T) region, 90<M(T)<200 GeV. The result is Gamma(W)=2032 +/- 45(stat)+/-57(syst) MeV, consistent with the standard model expectation.

Cross-section-constrained top-quark mass measurement from dilepton events at the Tevatron

We report the first top-quark mass measurement that uses a cross-section constraint to improve the mass determination. This measurement is made with a dilepton tt event candidate sample collected with the Collider Detector II at Fermilab. From a data sample corresponding to an integrated luminosity of 1.2 fb(-1), we measure a top-quark mass of 170.7(-3.9)(+4.2)(stat)+/-2.6(syst)+/-2.4(theory) GeV/c(2). The measurement without the cross-section constraint is 169.7(-4.9)(+5.2)(stat)+/-3.1(syst) GeV/c(2).

A neurocomputational model of figure-ground discrimination and target tracking

A neurocomputational model is presented for figureground discrimination and target tracking. In the model, the elementary motion detectors of the correlation type, the computational modules of saccadic and smooth pursuit eye movement, an oscillatory neural-network motion perception module and a selective attention module are involved. It is shown that through the oscillatory amplitude and frequency encoding, and selective synchronization of phase oscillators, the figure and the ground can be successfully discriminated from each other. The receptive fields developed by hidden units of the networks were surprisingly similar to the actual receptive fields and columnar organization found in the primate visual cortex. It is suggested that equivalent mechanisms may exist in the primate visual cortex to discriminate figure-ground in both temporal and spatial domains.

Search for standard model Higgs bosons produced in association with W bosons

We report on the results of a search for standard model Higgs bosons produced in association with W bosons from pp[over] collisions at sqrt[s]=1.96 TeV. The search uses a data sample corresponding to approximately 1 fb(-1) of integrated luminosity. Events consistent with the W-->lnu and H-->bb[over] signature are selected by triggering on a high-p(T) electron or muon candidate and tagging one or two of the jet candidates as having originated from b quarks. A neural network filter rejects a fraction of tagged charm and light-flavor jets, increasing the b-jet purity in the sample. We observe no excess lnubb[over] production beyond the background expectation, and we set 95% confidence level upper limits on the production cross section times branching fraction sigma(pp[over]-->WH)Br(H-->bb[over]) ranging from 3.9 to 1.3 pb, for specific Higgs boson mass hypotheses in the range 110 to 150 GeV/c2, respectively.

First observation of the decay Bs0-->Ds-Ds+ and measurement of its branching ratio

We report the observation of the exclusive decay Bs0-->Ds-Ds+ at the 7.5 standard deviation level using 355 pb(-1) of data collected by the CDF II detector in pp collisions at sqrt[s]=1.96 TeV at the Fermilab Tevatron. We measure the relative branching ratio B(Bs0-->Ds-Ds+)/B(B0-->D-Ds+)=1.44(-0.44)(+0.48). Using the world average value for B(B0-->D-Ds+), we find B(Bs0-->Ds-Ds+)=(9.4(-4.2)(+4.4))x10(-3). This provides a lower bound DeltaGammasCP/Gammas>or=2B(Bs0-->Ds-Ds+)>1.2x10(-2) at 95% C.L.

Crosstalk between the SUMO and ubiquitin pathways

Several ways in which the SUMO and ubiquitin pathways can intersect and communicate have recently been discovered. This review discusses the principles of crosstalk between SUMOylation and ubiquitination, focusing on the RNF4 family of RING finger E3 ubiquitin ligases, which specifically recognize SUMOylated proteins via their SUMO moiety for ubiquitination.