127 research outputs found
Search for a Technicolor omega_T Particle in Events with a Photon and a b-quark Jet at CDF
If the Technicolor omega_T particle exists, a likely decay mode is omega_T ->
gamma pi_T, followed by pi_T -> bb-bar, yielding the signature gamma bb-bar. We
have searched 85 pb^-1 of data collected by the CDF experiment at the Fermilab
Tevatron for events with a photon and two jets, where one of the jets must
contain a secondary vertex implying the presence of a b quark. We find no
excess of events above standard model expectations. We express the result of an
exclusion region in the M_omega_T - M_pi_T mass plane.Comment: 14 pages, 2 figures. Available from the CDF server (PS with figs):
http://www-cdf.fnal.gov/physics/pub98/cdf4674_omega_t_prl_4.ps
FERMILAB-PUB-98/321-
Evaluation of Oxfendazole, Praziquantel and Albendazole against Cystic Echinococcosis: A Randomized Clinical Trial in Naturally Infected Sheep
Cystic Echinococcosis (CE) is a near-cosmopolitan parasitic zoonosis that causes economic losses in many regions of the world. This parasitic infection can be regarded as an emerging or re-emerging disease causing considerable losses in livestock production. CE is produced by the larval cystic stage (hydatid) of the dog parasite Echinococcus granulosus. After infective eggs are ingested, cysts develop mainly in lungs and liver of humans and animals (sheep, cattle, pigs, horses, etc). Infected people may require surgery and/or Albendazole-based chemotherapy. In this study, we evaluated the effects of Oxfendazole alone (an antiparasitic drug used in animals), Oxfendazole plus Praziquantel, and Albendazole plus Praziquantel against hydatid cysts in sheep over 4 to 6 weeks of treatment. All of the treatments in this study were efficacious in killing the larval stages and, therefore, in minimizing the risk of a dog acquiring new infections (taenias). These treatment schemes can be added to control measures in animals and eventually could be used for the treatment of human infection. Further investigations on different schedules of monotherapy or combined chemotherapy are needed, as well as studies to evaluate the safety and efficacy of Oxfendazole in humans
Comparative pharmacokinetics and bioavailability of albendazole sulfoxide in sheep and goats, and dose-dependent plasma disposition in goats
Combining dark energy survey science verification data with near-infrared data from the ESO VISTA hemisphere survey
We present the combination of optical data from the Science Verification
phase of the Dark Energy Survey (DES) with near infrared data from the ESO
VISTA Hemisphere Survey (VHS). The deep optical detections from DES are used to
extract fluxes and associated errors from the shallower VHS data. Joint 7-band
() photometric catalogues are produced in a single 3 sq-deg DECam
field centred at 02h26m04d36m where the availability of ancillary
multi-wavelength photometry and spectroscopy allows us to test the data
quality. Dual photometry increases the number of DES galaxies with measured VHS
fluxes by a factor of 4.5 relative to a simple catalogue level matching
and results in a 1.5 mag increase in the 80\% completeness limit of the
NIR data. Almost 70\% of DES sources have useful NIR flux measurements in this
initial catalogue. Photometric redshifts are estimated for a subset of galaxies
with spectroscopic redshifts and initial results, although currently limited by
small number statistics, indicate that the VHS data can help reduce the
photometric redshift scatter at both . We present example
DES+VHS colour selection criteria for high redshift Luminous Red Galaxies
(LRGs) at as well as luminous quasars. Using spectroscopic
observations in this field we show that the additional VHS fluxes enable a
cleaner selection of both populations with 10\% contamination from galactic
stars in the case of spectroscopically confirmed quasars and
contamination from galactic stars in the case of spectroscopically confirmed
LRGs. The combined DES+VHS dataset, which will eventually cover almost 5000
sq-deg, will therefore enable a range of new science and be ideally suited for
target selection for future wide-field spectroscopic surveys.We thank the referee, Nicholas Cross, for a very useful report on
this manuscript. MB acknowledges a postdoctoral fellowship via
OL’s Advanced European Research Council Grant (TESTDE).
Funding for the DES Projects has been provided by the U.S.
Department of Energy, the U.S. National Science Foundation, the
Ministry of Science and Education of Spain, the Science and Technology
Facilities Council of the United Kingdom, the Higher Education
Funding Council for England, the National Center for Supercomputing
Applications at the University of Illinois at Urbana-
Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, Financiadora de Estudos e Projetos, Fundac¸ ˜ao
Carlos Chagas Filho de Amparo `a Pesquisa do Estado do Rio de
Janeiro, Conselho Nacional de Desenvolvimento Cient´ıfico e Tecnol
´ogico and the Minist´erio da Ciˆencia e Tecnologia, the Deutsche
Forschungsgemeinschaft and the Collaborating Institutions in the
Dark Energy Survey.
The Collaborating Institutions are Argonne National Laboratories,
the University of California at Santa Cruz, the University of
Cambridge, Centro de Investigaciones Energeticas, Medioambientales
y Tecnologicas-Madrid, the University of Chicago, University
College London, the DES-Brazil Consortium, the Eidgen¨ossische
Technische Hochschule (ETH) Z¨urich, Fermi National Accelerator
Laboratory, the University of Edinburgh, the University of
Illinois at Urbana-Champaign, the Institut de Ciencies de l’Espai
(IEEC/CSIC), the Institut de Fisica d’Altes Energies, the Lawrence
Berkeley National Laboratory, the Ludwig-Maximilians Universit
¨at and the associated Excellence Cluster Universe, the University
of Michigan, the National Optical Astronomy Observatory,
the University of Nottingham, The Ohio State University, the University
of Pennsylvania, the University of Portsmouth, SLAC National
Laboratory, Stanford University, the University of Sussex,
and Texas A&M University.
The DES participants from Spanish institutions are partially
supported by MINECO under grants AYA2009-13936, AYA2012-
39559, AYA2012-39620, and FPA2012-39684, which include
FEDER funds from the European Union.
We are grateful for the extraordinary contributions of our
CTIO colleagues and the DES Camera, Commissioning and Science
Verification teams in achieving the excellent instrument and
telescope conditions that have made this work possible. The success
of this project also relies critically on the expertise and dedication
of the DES Data Management organisation.
The analysis presented here is based on observations obtained
as part of the VISTA Hemisphere Survey, ESO Progam, 179.A-
2010 (PI: McMahon) and data products from observations made
with ESO Telescopes at the La Silla Paranal Observatory under
programme ID 179.A-2006 (PI: Jarvis).
Data for the OzDES spectroscopic survey were obtained with
the Anglo-Australian Telescope (program numbers 12B/11 and
13B/12). Parts of this research were conducted by the Australian
Research Council Centre of Excellence for All-sky Astrophysics
(CAASTRO), through project number CE110001020. TMD acknowledges
the support of the Australian Research Council through
Future Fellowship, FT100100595.This is the final published version. It first appeared at http://mnras.oxfordjournals.org/content/446/3/2523.abstract
Anthelmintic efficiency of doramectin, fenbendazole, and nitroxynil, in combination or individually, in sheep worm control
Search for second generation leptoquarks in the dimuon plus dijet channel of p-pbar collisions at sqrt{s}=1.8 TeV
We report on a search for second generation leptoquarks (Phi_2) using a data
sample corresponding to an integrated luminosity of 110 pb^{-1} collected at
the Collider Detector at Fermilab. We present upper limits on the production
cross section as a function of Phi_2 mass, assuming that the leptoquarks are
produced in pairs and decay into a muon and a quark with branching ratio beta.
Using a Next-to-Leading order QCD calculation, we extract a lower mass limit of
M_{\Phi_2} > 202 (160) GeV$/c^{2} at 95% confidence level for scalar
leptoquarks with beta=1(0.5).Comment: 11 pages, 2 figure
Search for New Particles Decaying to b bbar in p pbar Collisions at sqrt{s}=1.8 TeV
We have used 87 pb^-1 of data collected with the Collider Detector at
Fermilab to search for new particles decaying to b bbar. We present
model-independent upper limits on the cross section for narrow resonances which
excludes the color-octet technirho in the mass interval 350 < M < 440 GeV/c^2.
In addition, we exclude topgluons, predicted in models of topcolor-assisted
technicolor, of width Gamma = 0.3 M in the mass range 280 < M < 670 GeV/c^2, of
width Gamma = 0.5 M in the mass range 340 < M < 640 GeV/c^2, and of width Gamma
= 0.7 M in the mass range 375 < M < 560 GeV/c^2.Comment: 17 pages in a LaTex generated postscript file, with one table and
four figures. Resubmitted to Physical Review Letters. Minor clarifications
were added to the text. The displayed normalization of the resonance models
in Figure 2 was modified to correspond to our 95% CL upper limit on the cross
section (instead of arbitrary normalization which was used previously). All
results are identical to those in the previous submissio
Search for a W' Boson via the Decay Mode W' -> mu nu in 1.8 TeV p-pbar Collisions
We report the results of a search for a W' boson produced in p-pbar
collisions at a center-of-mass energy of 1.8 TeV using a 107 pb-1 data sample
recorded by the Collider Detector at Fermilab. We consider the decay channel W'
-> mu nu and search for anomalous production of high transverse mass mu-nu
lepton pairs. We observe no excess of events above background and set limits on
the rate of W' boson production and decay relative to Standard Model W boson
production and decay using a fit of the transverse mass distribution observed.
If we assume Standard Model strength couplings of the W' boson to quark and
lepton pairs, we exclude a W' boson with invariant mass less than 660 GeV/c**2
at 95% confidence level.Comment: 19 pages, 2 figure
Localization and broadband follow-up of the gravitational-wave transient GW150914
A gravitational-wave (GW) transient was identified in data recorded by the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) detectors on 2015 September 14. The event, initially designated G184098 and later given the name GW150914, is described in detail elsewhere. By prior arrangement, preliminary estimates of the time, significance, and sky location of the event were shared with 63 teams of observers covering radio, optical, near-infrared, X-ray, and gamma-ray wavelengths with ground- and space-based facilities. In this Letter we describe the low-latency analysis of the GW data and present the sky localization of the first observed compact binary merger. We summarize the follow-up observations reported by 25 teams via private Gamma-ray Coordinates Network circulars, giving an overview of the participating facilities, the GW sky localization coverage, the timeline, and depth of the observations. As this event turned out to be a binary black hole merger, there is little expectation of a detectable electromagnetic (EM) signature. Nevertheless, this first broadband campaign to search for a counterpart of an Advanced LIGO source represents a milestone and highlights the broad capabilities of the transient astronomy community and the observing strategies that have been developed to pursue neutron star binary merger events. Detailed investigations of the EM data and results of the EM follow-up campaign are being disseminated in papers by the individual teams
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
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