268 research outputs found
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
Atmospheric neutrinos in a Large Liquid Argon detector
In view of the evaluation of the physics goals of a large Liquid Argon TPC,
evolving from the ICARUS technology, we have studied the possibility of
performing precision measurements on atmospheric neutrinos. For this purpose we
have improved existing Monte Carlo neutrino event generators based on FLUKA and
NUX by including the 3-flavor oscillation formalism and the numerical treatment
of Earth matter effects. By means of these tools we have studied the
sensitivity in the measurement of Theta(23) through the accurate measurement of
electron neutrinos. The updated values for Delta m^2(23) from Super-Kamiokande
and the mixing parameters as obtained by solar and KamLand experiments have
been used as reference input, while different values of Theta(13) have been
considered. An exposure larger than 500 kton yr seems necessary in order to
achieve a significant result, provided that the present knowledge of systematic
uncertainties is largely improved.Comment: Talk given at the worksgop "Cryogenic Liquid Detectors for Future
Particle Physics", LNGS (Italy) March 13th-14th, 200
Neutrino telescopes and high-energy cosmic neutrinos
In this review paper, we present the main aspects of high-energy cosmic neutrino astrophysics. We begin by describing the generic expectations for cosmic neutrinos, including the effects of propagation from their sources to the detectors. Then we introduce the operating principles of current neutrino telescopes, and examine the main features (topologies) of the observable events. After a discussion of the main background processes, due to the concomitant presence of secondary particles produced in the terrestrial atmosphere by cosmic rays, we summarize the current status of the observations with astrophysical relevance that have been greatly contributed by IceCube detector. Then, we examine various interpretations of these findings, trying to assess the best candidate sources of cosmic neutrinos. We conclude with a brief perspective on how the field could evolve within a few years
The likelihood for supernova neutrino analyses
We derive the event-by-event likelihood that allows to extract the complete
information contained in the energy, time and direction of supernova neutrinos,
and specify it in the case of SN1987A data. We resolve discrepancies in the
previous literature, numerically relevant already in the concrete case of
SN1987A data.Comment: 7 pages, 2 figures. Accepted for publication in PR
Observables sensitive to absolute neutrino masses: Constraints and correlations from world neutrino data
In the context of three-flavor neutrino mixing, we present a thorough study
of the phenomenological constraints applicable to three observables sensitive
to absolute neutrino masses: The effective neutrino mass in Tritium beta decay
(m_beta); the effective Majorana neutrino mass in neutrinoless double beta
decay (m_2beta); and the sum of neutrino masses in cosmology (Sigma). We
discuss the correlations among these variables which arise from the combination
of all the available neutrino oscillation data, in both normal and inverse
neutrino mass hierarchy. We set upper limits on m_beta by combining updated
results from the Mainz and Troitsk experiments. We also consider the latest
results on m_2beta from the Heidelberg-Moscow experiment, both with and without
the lower bound claimed by such experiment. We derive upper limits on Sigma
from an updated combination of data from the Wilkinson Microwave Anisotropy
Probe (WMAP) satellite and the 2 degrees Fields (2dF) Galaxy Redshifts Survey,
with and without Lyman-alpha forest data from the Sloan Digital Sky Survey
(SDSS), in models with a non-zero running of the spectral index of primordial
inflationary perturbations. The results are discussed in terms of
two-dimensional projections of the globally allowed region in the
(m_beta,m_2beta,Sigma) parameter space, which neatly show the relative impact
of each data set. In particular, the (in)compatibility between Sigma and
m_2beta constraints is highlighted for various combinations of data. We also
briefly discuss how future neutrino data (both oscillatory and non-oscillatory)
can further probe the currently allowed regions.Comment: 17 pages (RevTeX) + 7 figures (PostScript). Minor changes in text;
references added; results unchanged. To appear in PR
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