Gianni Fiorentini

Observation of Geo{Neutrinos

Geo–neutrinos, electron anti–neutrinos produced in β decays of naturally occurring radioactive isotopes in the Earth, are a unique direct probe of our planet’s interior. We report the first observation at more than 3σ C.L. of geo–neutrinos, performed with the Borexino detector at Laboratori Nazionali del Gran Sasso. Anti–neutrinos are detected through the neutron inverse β decay reaction. With a 252.6 ton·yr fiducial exposure after all selection cuts, we detected 9.9 −3.4( +14.6 −8.2 ) geo–neutrino events, with errors corresponding to a 68.3% (99.73%) C.L. From the lnL profile, the statistical significance of the Borexino geo-neutrino observation corresponds to a 99.997% C.L. Our measurement of the geo–neutrinos rate is 3.9 −1.3( +5.8 −3.2) events/(100 ton·yr). The observed prompt positron spectrum above 2.6 MeV is compatible with that expected from european nuclear reactors (mean base line of approximately 1000 km). Our measurement of reactor anti–neutrinos excludes the non-oscillation hypothesis at 99.60% C.L. This measurement rejects the hypothesis of an active geo-reactor in the Earth’s core with a power above 3 TW at 95% C.L.

Antineutrinos from Earth: A reference model and its uncertainties

We predict geoneutrino fluxes in a reference model based on a detailed description of Earths crust and mantle and using the best available information on the abundances of uranium, thorium, and potassium inside Earths 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

Geo-neutrinos and earth's interior

N(\mathrm{U}+\mathrm{Th})=35\ifmmode\pm\else\textpm\fi{}6

How much uranium is in the Earth? Predictions for geoneutrinos at KamLAND

events for

Geo-Neutrinos: a short review

{10}^{32}\mathrm{proton}\mathrm{yr}

Nuclear physics for geo-neutrino studies

and 100% efficiency assuming

KamLAND results and the radiogenic terrestrial heat

{\mathrm{sin}}^{2}(2\ensuremath{\theta})=0.863

The cross section of 3He(3He,2p)4He measured at solar energies

and

Supernova neutrinos and the ντ mass

\ensuremath{\delta}{m}^{2}=7.3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}{\mathrm{eV}}^{2}.

Relativistic effects on the solar radius

The maximal prediction is 55 events, obtained in a model with fully radiogenic production of the terrestrial heat flow.