552 research outputs found
Dynamical Behavior of an Eco-epidemiological Model Incorporating Prey Refuge and Prey Harvesting
In this paper an eco-epidemiological model incorporating a prey refuge and prey harvesting with disease in the prey-population is considered. Predators are assumed to consume both the susceptible and infected prey at different rates. The positivity and boundedness of the solution of the system are discussed. The existence and stability of the biologically feasible equilibrium points are investigated. Numerical simulations are performed to support our analytical findings
Contribution of Sex-linked Biology and Gender Roles to Disparities with Trachoma1
Gender roles, rather than biology, dictate why trachoma is more common in women
A case report of an asymptomatic late term abdominal pregnancy with a live birth at 41 weeks of gestation
Observation of Hadronic W Decays in t-tbar Events with the Collider Detector at Fermilab
We observe hadronic W decays in t-tbar -> W (-> l nu) + >= 4 jet events using
a 109 pb-1 data sample of p-pbar collisions at sqrt{s} = 1.8 TeV collected with
the Collider Detector at Fermilab (CDF). A peak in the dijet invariant mass
distribution is obtained that is consistent with W decay and inconsistent with
the background prediction by 3.3 standard deviations. From this peak we measure
the W mass to be 77.2 +- 4.6 (stat+syst) GeV/c^2. This result demonstrates the
presence of two W bosons in t-tbar candidates in the W (-> l nu) + >= 4 jet
channel.Comment: 20 pages, 4 figures, submitted to PR
Search for charged Higgs decays of the top quark using hadronic tau decays
We present the result of a search for charged Higgs decays of the top quark,
produced in collisions at 1.8 TeV. When the charged
Higgs is heavy and decays to a tau lepton, which subsequently decays
hadronically, the resulting events have a unique signature: large missing
transverse energy and the low-charged-multiplicity tau. Data collected in the
period 1992-1993 at the Collider Detector at Fermilab, corresponding to
18.70.7~pb, exclude new regions of combined top quark and charged
Higgs mass, in extensions to the standard model with two Higgs doublets.Comment: uuencoded, gzipped tar file of LaTeX and 6 Postscript figures; 11 pp;
submitted to Phys. Rev.
Measurement of the lepton charge asymmetry in W-boson decays produced in p-pbar collisions
We describe a measurement of the charge asymmetry of leptons from W boson
decays in the rapidity range 0 enu, munu events from
110+/-7 pb^{-1}of data collected by the CDF detector during 1992-95. The
asymmetry data constrain the ratio of d and u quark momentum distributions in
the proton over the x range of 0.006 to 0.34 at Q2 \approx M_W^2. The asymmetry
predictions that use parton distribution functions obtained from previously
published CDF data in the central rapidity region (0.0<|y_l|<1.1) do not agree
with the new data in the large rapidity region (|y_l|>1.1).Comment: 13 pages, 3 tables, 1 figur
Inclusive jet cross section in collisions at TeV
The inclusive jet differential cross section has been measured for jet
transverse energies, , from 15 to 440 GeV, in the pseudorapidity region
0.10.7. The results are based on 19.5 pb of data
collected by the CDF collaboration at the Fermilab Tevatron collider. The data
are compared with QCD predictions for various sets of parton distribution
functions. The cross section for jets with GeV is significantly
higher than current predictions based on O() perturbative QCD
calculations. Various possible explanations for the high- excess are
discussed.Comment: 8 pages with 2 eps uu-encoded figures Submitted to Physical Review
Letter
Measurement of the Associated Production Cross Section in Collisions at TeV
We present the first measurement of associated direct photon + muon
production in hadronic collisions, from a sample of 1.8 TeV
collisions recorded with the Collider Detector at Fermilab. Quantum
chromodynamics (QCD) predicts that these events are primarily from the Compton
scattering process , with the final state charm quark producing
a muon. Hence this measurement is sensitive to the charm quark content of the
proton. The measured cross section of is compared to a
leading-order QCD parton shower model as well as a next-to-leading-order QCD
calculation.Comment: 12 pages, 4 figures Added more detailed description of muon
background estimat
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