577 research outputs found
Extraction of Semantic Relations from Wikipedia Text Corpus
This paper proposes the algorithm for automatic extraction of semantic relations using the rule-based approach. The authors suggest identifying certain verbs (predicates) between a subject and an object of expressions to obtain a sequence of semantic relations in the designed text corpus of Wikipedia articles. The synsets from WordNet are applied to extract semantic relations between concepts and their synonyms from the text corpus
Fiber technology applications for a future e+e- linear collider detector
The advantages and possibilities of fiber technology for the detection of
particles in 500 GeV e+e- reactions are considered. It is suggested to build a
fast trigger which could be used also for intermediate tracking. A fiber
preshower in front of the electromagnetic calorimeter would allow to identify
electrons and photons with a space precision better than 0.1 mm.Comment: 7 pages, 9 figures. Contributed to Workshop on Scintillating Fiber
Detectors (SCIFI97), Notre Dame, IN, 2-6 Nov 199
Deeply-Virtual Compton Scattering on Deuterium and Neon at HERMES
We report the first observation of azimuthal beam-spin asymmetries in hard
electroproduction of real photons off nuclei. Attributed to the interference
between the Bethe-Heitler process and the deeply-virtual Compton scattering
process, the asymmetry gives access to the latter at the amplitude level. This
process appears to be the theoretically cleanest way to access generalized
parton distributions. The data presented here have been accumulated by the
HERMES experiment at DESY, scattering the HERA 27.6 GeV positron beam off
deuterium and neon gas targets.Comment: 5 pages, 6 figures. Talk given by F. Ellinghaus at the "15th
International Spin Physics Symposium", SPIN 2002, September 9-14, 2002, BNL,
Upton, NY, USA. To be published in the proceeding
Measuring the Higgs Branching Fraction into two Photons at Future Linear \ee Colliders
We examine the prospects for measuring the \gaga branching fraction of a
Standard Model-like Higgs boson with a mass of 120 GeV at the future TESLA
linear \ee collider, assuming an integrated luminosity of 1 ab and
center-of-mass energies of 350 GeV and 500 GeV. The Higgs boson is produced in
association with a fermion pair via the Higgsstrahlung process \ee ,
with \qq or \nn, or the WW fusion reaction . A relative uncertainty on BF(\hgg) of~16% can be achieved in
unpolarized \ee collisions at =~500 GeV, while for =~350
GeV the expected precision is slightly poorer. With appropriate initial state
polarizations BF(\hgg)/BF(\hgg) can be improved to 10%. If this
measurement is combined with the expected error for the total Higgs width, a
precision of 10% on the \gaga Higgs boson partial width appears feasible.Comment: 14 pages, 5 figure
Sensitivity studies for the cubic-kilometre deep-sea neutrino telescope KM3NeT
The observation of high-energy neutrinos from astrophysical sources would
substantially improve our knowledge and understanding of the non-thermal
processes in these sources, and would in particular pinpoint the accelerators
of cosmic rays. The sensitivity of different design options for a future
cubic-kilometre scale neutrino telescope in the Mediterranean Sea is
investigated for generic point sources and in particular for some of the
galactic objects from which TeV gamma emmission has recently been observed by
the H.E.S.S. atmospheric Cherenkov telescope. The effect of atmospheric
background on the source detection probabilities has been taken into account
through full simulation. The estimated event rates are compared to previous
results and limits from present neutrino telescopes.Comment: 4 pages, 1 figure, contribution of the 30th International Cosmic Ray
conferenc
Testrun results from prototype fiber detectors for high rate particle tracking
A fiber detector concept has been realized allowing to registrate particles
within less than 100 nsec with a space point precision of about 0.1 mm at low
occupancy. Three full size prototypes have been build by different producers
and tested at a 3 GeV electron beam at DESY. After 3 m of light guides 8-10
photoelectrons were registrated by multichannel photomultipliers providing an
efficiency of more than 99%. Using all available data a resolution of 0.086 mm
was measured.Comment: 18 pages, 17 figure
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