53 research outputs found
Discriminating among Earth composition models using geo-antineutrinos
It has been estimated that the entire Earth generates heat corresponding to
about 40 TW (equivalent to 10,000 nuclear power plants) which is considered to
originate mainly from the radioactive decay of elements like U, Th and K,
deposited in the crust and mantle of the Earth. Radioactivity of these elements
produce not only heat but also antineutrinos (called geo-antineutrinos) which
can be observed by terrestrial detectors. We investigate the possibility of
discriminating among Earth composition models predicting different total
radiogenic heat generation, by observing such geo-antineutrinos at Kamioka and
Gran Sasso, assuming KamLAND and Borexino (type) detectors, respectively, at
these places. By simulating the future geo-antineutrino data as well as reactor
antineutrino background contributions, we try to establish to which extent we
can discriminate among Earth composition models for given exposures (in units
of kt yr) at these two sites on our planet. We use also information on
neutrino mixing parameters coming from solar neutrino data as well as KamLAND
reactor antineutrino data, in order to estimate the number of geo-antineutrino
induced events.Comment: 24 pages, 10 figures, final version to appear in JHE
Antineutrinos from Earth: A reference model and its uncertainties
We predict geoneutrino fluxes in a reference model based on a detailed
description of Earth's crust and mantle and using the best available
information on the abundances of uranium, thorium, and potassium inside Earth's
layers. We estimate the uncertainties of fluxes corresponding to the
uncertainties of the element abundances. In addition to distance integrated
fluxes, we also provide the differential fluxes as a function of distance from
several sites of experimental interest. Event yields at several locations are
estimated and their dependence on the neutrino oscillation parameters is
discussed. At Kamioka we predict N(U+Th)=35 +- 6 events for 10^{32} proton yr
and 100% efficiency assuming sin^2(2theta)=0.863 and delta m^2 = 7.3 X 10^{-5}
eV^2. The maximal prediction is 55 events, obtained in a model with fully
radiogenic production of the terrestrial heat flow.Comment: 24 pages, ReVTeX4, plus 7 postscript figures; minor formal changes to
match version to be published in PR
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