118 research outputs found
Can there be neutrino oscillation in Gamma-Ray Bursts fireball ?
The central engine which powers the Gamma-Ray Burst (GRB) fireball, produces
neutrinos in the energy range of about 5-20 MeV. Fractions of these neutrinos
may propagate through the fireball which is far away from the central engine.
We have studied the propagation of these neutrinos through the fireball which
is contaminated by baryons and have shown that, resonant conversion of
neutrinos are possible for the oscillations of nu_e to nu_{mu,tau}, nu_e to
nu_s and anti-nu_(mu,tou) to anti-nu_s if the neutrino mass square difference
and mixing angle are in the atmospheric and/or LSND range. On the other hand it
is probably difficult for neutrinos to have resonant oscillation if the
neutrino parameters are in the solar neutrino range. From the resonance
condition we have estimated the fireball temperature and the baryon load in it.Comment: 4 pages, two column text, To be published in Phys. Rev.
Oscillation tomografy study of Earth's composition and density with atmospheric neutrinos
Knowledge of the composition of the Earth's interior is highly relevant to
many geophysical and geochemical problems. Neutrino oscillations are modified
in a non-trivial way by the matter effects and can provide valuable and unique
information not only on the density but also on the chemical and isotopic
composition of the deep regions of the planet. In this paper, we re-examine the
possibility of performing an oscillation tomography of the Earth with
atmospheric neutrinos and antineutrinos to obtain information on the
composition and density of the outer core and the mantle, complementary to that
obtained by geophysical methods. Particular attention is paid to the D layer just above the core-mantle boundary and to the water (hydrogen)
content in the mantle transition zone. Our analysis is based on a Monte-Carlo
simulation of the energy and azimuthal angle distribution of -like events
generated by neutrinos. Taking as reference a model of the Earth consisting of
55 concentric layers with constant densities determined from the PREM, we
evaluate the effect on the number of events due to changes in the composition
and density of the outer core and the mantle. To examine the capacity of a
detector like ORCA to resolve such variations, we construct regions in planes
of two of these quantities where the statistical significance of the
discrepancies between the reference and the modified Earth are less than
. The variations are implemented in such a way that the constraint
imposed by both the total mass of the Earth and its moment of inertia are
verified.Comment: Already published in the European Physical Journal
Cherenkov radiation by massless neutrinos
Due to their weak interactions, neutrinos can polarize a medium and acquire
an induced charge. We consider the Cherenkov radiation emitted by neutrinos due
to their effective electromagnetic interactions as they pass through a
polarizable medium. The effect exists even for massless, chiral neutrinos,
where no physics beyond the standard model needs to be assumed.Comment: 11 pages Latex file; to appear in Phys. Lett.
Earth tomography with atmospheric neutrino oscillations
The study of the flux of atmospheric neutrino crossing the Earth can provide useful information not only on the matter density of the different layers that make up the planet but also on their chemical composition. The key phenomenon that makes this possible is flavor oscillations and their dependence on the electron density along the neutrino baseline. To extract the relevant information, we simulate the energy and azimuth angle distribution of events produced in a generic neutrino telescope by atmospheric neutrinos passing through the deepest parts of the Earth. Changes in the densities of the outer core and the mantle are implemented by varying the location of the boundary between these layers so that the restrictions on the mass of and the moment of inertia of the Earth are both satisfied. This allows us to examine the effect of simultaneous changes in composition and density of the outer core, unlikely other works on the subject, where only one of these quantities was varied.Fil: D'Olivo, Juan Carlos. Universidad Nacional Autónoma de México. Instituto de Ciencias Nucleares; MéxicoFil: Herrera Lara, José Arnulfo. Universidad Nacional Autónoma de México. Instituto de Ciencias Nucleares; MéxicoFil: Romero, Ismael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Sampayo, Oscar Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Zapata, Gabriel Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentin
DAMIC at SNOLAB
We introduce the fully-depleted charge-coupled device (CCD) as a particle
detector. We demonstrate its low energy threshold operation, capable of
detecting ionizing energy depositions in a single pixel down to 50 eVee. We
present results of energy calibrations from 0.3 keVee to 60 keVee, showing that
the CCD is a fully active detector with uniform energy response throughout the
silicon target, good resolution (Fano ~0.16), and remarkable linear response to
electron energy depositions. We show the capability of the CCD to localize the
depth of particle interactions within the silicon target. We discuss the mode
of operation and unique imaging capabilities of the CCD, and how they may be
exploited to characterize and suppress backgrounds. We present the first
results from the deployment of 250 um thick CCDs in SNOLAB, a prototype for the
upcoming DAMIC100. DAMIC100 will have a target mass of 0.1 kg and should be
able to directly test the CDMS-Si signal within a year of operation.Comment: 13 pages, 12 figures, proceedings prepared for 13th International
Conference on Topics in Astroparticle and Underground Physics (TAUP2013
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