47 research outputs found
Sensitivity on Earth Core and Mantle densities using Atmospheric Neutrinos
Neutrino radiography may provide an alternative tool to study the very deep
structures of the Earth. Though these measurements are unable to resolve the
fine density layer features, nevertheless the information which can be obtained
are independent and complementary to the more conventional seismic studies. The
aim of this paper is to assess how well the core and mantle averaged densities
can be reconstructed through atmospheric neutrino radiography. We find that
about a 2% sensitivity for the mantle and 5% for the core could be achieved for
a ten year data taking at an underwater km^3 Neutrino Telescope. This result
does not take into account systematics related to the details of the
experimental apparatus.Comment: 11 pages, 11 figures, accepted for publication in JCA
Neutrino Telescopes' Sensitivity to Dark Matter
The nature of the dark matter of the Universe is yet unknown and most likely
is connected with new physics. The search for its composition is under way
through direct and indirect detection. Fundamental physical aspects such as
energy threshold, geometry and location are taken into account to investigate
proposed neutrino telescopes of km^3 volume sensitivities to dark matter. These
sensitivities are just sufficient to test a few WIMP scenarios. Telescopes of
km^3 volume, such as IceCube, can definitely discover or exclude superheavy (M
> 10^10 GeV) Strong Interacting Massive Particles (Simpzillas). Smaller
neutrino telescopes such as ANTARES, AMANDA-II and NESTOR can probe a large
region of the Simpzilla parameter space.Comment: 28 pages, 9 figure
Geotomography with solar and supernova neutrinos
We show how by studying the Earth matter effect on oscillations of solar and
supernova neutrinos inside the Earth one can in principle reconstruct the
electron number density profile of the Earth. A direct inversion of the
oscillation problem is possible due to the existence of a very simple analytic
formula for the Earth matter effect on oscillations of solar and supernova
neutrinos. From the point of view of the Earth tomography, these oscillations
have a number of advantages over the oscillations of the accelerator or
atmospheric neutrinos, which stem from the fact that solar and supernova
neutrinos are coming to the Earth as mass eigenstates rather than flavour
eigenstates. In particular, this allows reconstruction of density profiles even
over relatively short neutrino path lengths in the Earth, and also of
asymmetric profiles. We study the requirements that future experiments must
meet to achieve a given accuracy of the tomography of the Earth.Comment: 35 pages, 7 figures; minor textual changes in section
Measuring Atmospheric Neutrino Oscillations with Neutrino Telescopes
Neutrino telescopes with large detection volumes can demonstrate that the
current indications of neutrino oscillation are correct or if a better
description can be achieved with non-standard alternatives. Observations of
contained muons produced by atmospheric neutrinos can better constrain the
allowed region for oscillations or determine the relevant parameters of
non-standard models. We analyze the possibility of neutrino telescopes
measuring atmospheric neutrino oscillations. We suggest adjustments to improve
this potential. An addition of four densely-instrumented strings to the AMANDA
II detector makes observations feasible. Such a configuration is competitive
with current and proposed experiments.Comment: 36 pages, 21 figures, revte
Comparing and contrasting the and solutions to the atmospheric neutrino problem with SuperKamiokande data
The and solutions to the
atmospheric neutrino problem are compared with SuperKamiokande data. The
differences between these solutions due to matter effects in the Earth are
calculated for the ratio of -like to -like events and for up-down flux
asymmetries. These quantities are chosen because they are relatively
insensitive to theoretical uncertainties in the overall neutrino flux
normalisation and detection cross-sections and efficiencies. A
analysis using these quantities is performed yielding ranges which
are approximately given by and for
for the and solutions, respectively. Values of smaller than about
eV are disfavoured for the
solution, suggesting that future long baseline experiments should see a
positive signal if this scenario is the correct one.Comment: revtex, 22 pages, 12 figure
The energy spectrum of tau leptons induced by the high energy Earth-skimming neutrinos
We present a semi-analytic calculation of the tau-lepton flux emerging from
the Earth, induced by the incident high energy neutrinos interacting inside the
Earth for . We obtain results for
the energy dependence of the tau-lepton flux coming from the Earth-skimming
neutrinos, because of the neutrino-nucleon charged-current scattering as well
as the resonant scattering. We illustrate our results for
several anticipated high energy astrophysical neutrino sources such as the
AGNs, the GRBs, and the GZK neutrino fluxes. The tau lepton fluxes resulting
from rock-skimming and ocean-skimming neutrinos are compared. Such comparisons
can render useful information for the spectral indices of incident neutrino
fluxes.Comment: 23 pages, 6 figure
Future Oscillation Experiments and Present Data
Our goal in this paper is to examine the discovery potential of laboratory
experiments searching for the oscillation , in the light of recent data on solar and atmospheric neutrino
experiments, which we analyse together with the most restrictive results from
laboratory experiments on neutrino oscillations. In order to explain
simultaneously present results we use a four-neutrino framework, with an
additional sterile neutrino. Our predictions are rather pessimistic for the
upcoming experiments NOMAD and CHORUS, which, we find, are able to explore only
a small area of the oscillation parameter space. On the other hand, the
discovery potential of future experiments is much larger. We consider three
examples. E803, which is approved to operate in the future Fermilab main
injector beam line, MINOS, a proposed long-baseline experiment also using the
Fermilab beam, and NAUSICAA, an improved detector which improves by an order of
magnitude the performance of CHORUS/NOMAD and can be operated either at CERN or
at Fermilab beams. We find that those experiments can cover a very substantial
fraction of the oscillation parameter space, having thus a very good chance of
discovering and oscillation modes.Comment: Latex file using ReVTeX and epsifig.sty. 40 Pages. Revised version
includes new references and changed Fig.
Calculation of the Flux of Atmospheric Neutrinos
Atmospheric neutrino-fluxes are calculated over the wide energy range from 30
MeV to 3,000 GeV for the study of neutrino-physics using the data from
underground neutrino-detectors. The atmospheric muon-flux at high altitude and
at sea level is studied to calibrate the neutrino-fluxes at low energies and
high energies respectively. The agreement of our calculation with observations
is satisfactory. The uncertainty of atmospheric neutrino-fluxes is also
studied.Comment: 51 page