2,776 research outputs found
A reconstruction method for neutrino induced muon tracks taking into account the apriori knowledge of the neutrino source
Gamma ray earthbound and satellite experiments have discovered, over the last
years, many galactic and extra-galactic gamma ray sources. The detection of
astrophysical neutrinos emitted by the same sources would imply that these
astrophysical objects are charged cosmic ray accelerators and help to resolve
the enigma of the origin of cosmic rays. A very large volume neutrino telescope
might be able to detect these potential neutrino emitters. The apriori known
direction of the neutrino source can be used to effectively suppress the
optical background and increase significantly the tracking efficiency
through causality filters. We report on advancing filtering and prefit
techniques using the known neutrino source direction and first results are
presented.Comment: 10 pages, 4 figures, to be published in Nucl. Inst. and Meth. A v2:
minor changes, 1 page adde
KM3NeT:a large underwater neutrino telescope in the Mediterranean Sea
High energy neutrinos produced in astrophysical processes will allow for a
new way of studying the universe. In order to detect the expected flux of high
energy neutrinos from specific astrophysical sources, neutrino telescopes of a
scale of a km^3 of water will be needed. A Northern Hemisphere detector is
being proposed to be sited in a deep area of the Mediterranean Sea. This
detector will provide complimentary sky coverage to the IceCube detector being
built at the South Pole. The three neutrino telescope projects in the
Mediterranean (ANTARES, NEMO and NESTOR) are partners in an effort to design,
and build such a km^3 size neutrino telescope, the KM3NeT. The EU is funding a
3-year Design Study; the status of the Design Study is presented and some
technical issues are discussed.Comment: 4 pages, 3 figures, Prepared for the 10th International Conference on
Astroparticle and Underground Physics (TAUP 2007), Sendai, Japan, 11-15 Sep
200
Extended Modified Observable Technique for a Multi-Parametric Trilinear Gauge Coupling Estimation at LEP II
This paper describes the extension of the Modified Observables technique in
estimating simultaneously more than one Trilinear Gauge Couplings. The optimal
properties, unbiasedness and consistent error estimation of this method are
demonstrated by Monte Carlo experimentation using four-fermion
final state topologies. Emphasis is given in the determination of the expected
sensitivities in estimating the and
pair of couplings with data from the 183
GeV LEPII run.Comment: (17 pages, 8 figures
Evaluation of the discovery potential of an underwater Mediterranean neutrino telescope taking into account the estimated directional resolution and energy of the reconstructed tracks
We report on the development of search methods for point-like and extended
neutrino sources, utilizing the tracking and energy estimation capabilities of
an underwater, Very Large Volume Neutrino Telescope (VLVnT). We demonstrate
that the developed techniques offer a significant improvement on the
telescope's discovery potential. We also present results on the potential of
the Mediterranean KM3NeT to discover galactic neutrino sources.Comment: 12 pages, 1 figure, to be published in Nucl. Inst. and Meth. A v2:
minor changes, 1 page adde
Multidimensional Binning Techniques for a Two Parameter Trilinear Gauge Coupling Estimation at LEP II
This paper describes two generalization schemes of the Optimal Variables
technique in estimating simultaneously two Trilinear Gauge Couplings. The first
is an iterative procedure to perform a 2-dimensional fit using the linear terms
of the expansion of the probability density function with respect to the
corresponding couplings, whilst the second is a clustering method of
probability distribution representation in five dimensions. The pair production
of W's at 183 GeV center of mass energy, where one W decays leptonically and
the other hadronically, was used to demonstrate the optimal properties of the
proposed estimation techniques.Comment: (25 pages, 11 figures
Angular reconstruction of high energy air showers using the radio signal spectrum
The Hellenic Open University extensive air shower array (also known as
Astroneu array) is a small scale hybrid detection system operating in an area
with high levels of electromagnetic noise from anthropogenic activity. In the
present study we report the latest results of the data analysis concerning the
estimation of the shower direction using the spectrum of the RF system. In a
recent layout of the array, 4 RF antennas were operating receiving a common
trigger from an autonomous detection station of 3 particle detectors. The
directions estimated with the RF system are in very good agreement with the
corresponding estimations using the particle detectors demonstrating that a
single antenna has the potential for reconstructing the shower axis angular
direction
Reconstruction efficiency and discovery potential of a Mediterranean neutrino telescope: A simulation study using the Hellenic Open University Reconstruction & Simulation (HOURS) package
We report on the evaluation of the performance of a Mediterranean very large
volume neutrino telescope. We present results of our studies concerning the
capability of the telescope in detecting/discovering galactic (steady point
sources) and extragalactic, transient (Gamma Ray Bursts) high energy neutrino
sources as well as measuring ultra high energy diffuse neutrino fluxes. The
neutrino effective area and angular resolution are presented as a function of
the neutrino energy, and the background event rate (atmospheric neutrinos and
muons) is estimated. The discovery potential of the neutrino telescope is
evaluated and the experimental time required for a significant discovery of
potential neutrino emitters (known from their gamma ray emission, assumedly
produced by hadronic interactions) is estimated. For the simulation we use the
HOU Reconstruction & Simulation (HOURS) software package.Comment: 10 pages, 4 figures, to be published in Nucl. Inst. and Meth. A v2:
minor changes, 1 page adde
A Feasibility Study for the Detection of Supernova Explosions with an Undersea Neutrino Telescope
We study the potential of a very large volume underwater Mediterranean
neutrino telescope to observe neutrinos from supernova (SN) explosions within
our galaxy. The intense neutrino burst emitted in a SN explosion results in a
large number of MeV neutrinos inside the instrumented volume of the neutrino
telescope that can be detected (mainly) via the reaction \nu_e-bar + p -> e^+ +
n . In this study we simulated the response of the underwater neutrino
telescope to the electron antineutrino flux predicted by the Garching model for
SN explosions. We assumed that the neutrino telescope comprises 6160 direction
sensitive optical modules, each containing 31 small photomultiplier tubes.
Multiple coincidences between the photomultiplier tubes of the same optical
module are utilized to suppress the noise produced by radioactive
decays and to establish a statistical significant signature of the SN
explosion.Comment: 11 pages, 3 figures, to be published in Nucl. Inst. and Meth. A v2:
minor changes, 1 page adde
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