Geo-neutrinos and Earth's interior

The deepest hole that has ever been dug is about 12 km deep. Geochemists analyze samples from the Earth's crust and from the top of the mantle. Seismology can reconstruct the density profile throughout all Earth, but not its composition. In this respect, our planet is mainly unexplored. Geo-neutrinos, the antineutrinos from the progenies of U, Th and K40 decays in the Earth, bring to the surface information from the whole planet, concerning its content of natural radioactive elements. Their detection can shed light on the sources of the terrestrial heat flow, on the present composition, and on the origins of the Earth. Geo-neutrinos represent a new probe of our planet, which can be exploited as a consequence of two fundamental advances that occurred in the last few years: the development of extremely low background neutrino detectors and the progress on understanding neutrino propagation. We review the status and the prospects of the field.Comment: 56 pages in RMP ReVTeX format, 36 figures. A few typos corrected and a few minor points changed: resubmitted only to match the final version accepted for publication by Physics Report

Geo-neutrinos: a new probe of Earth's interior

In preparation to the experimental results which will be available in the future, we study geo-neutrino production for different models of mantle convection and composition. By using global mass balance for the Bulk Silicate Earth, the predicted flux contribution from distant sources in the crust and in the mantle is fixed within a total uncertainty of +-15%. We also discuss regional effects, provided by subducting slabs or plumes near the detector. In four years a five-kton detector operating at a site relatively far from nuclear power plants can achieve measurements of the geo-neutrino signal accurate to within +-5%. It will provide a crucial test of the Bulk Silicate Earth and a direct estimate of the radiogenic contribution to terrestrial heat.Comment: 19 pages, 6 tables, 7 figures; accepted for publication in Earth and Planetary Science Letter

KamLAND results and the radiogenic terrestrial heat

We find that recent results from the KamLAND collaboration on geologically produced antineutrinos, N(U+Th) = 28+16-15 events, correspond to a radiogenic heat production from Uranium and Thorium decay chains H(U+Th) = 38+35-33 TW. The 99% confidence limit on the geo-neutrino signal translates into the upper bound H(U+Th) < 162 TW, which is much weaker than that claimed by KamLAND, H(U+Th) < 60 TW, based on a too narrow class of geological models. We also performed an analysis of KamLAND data including recent high precision measurements of the C13(\alpha,n)O16 cross section. The result, N(U+Th) = 31+14-13, corroborates the evidence (approx 2.5\sigma) for geo-neutrinos in KamLAND data.Comment: 7 pages (RevTex), 2 figures. Minor changes that match the version accepted for publication on Phys. Lett.

Geo-Neutrinos: a short review

Geo-neutrino detection will determine the amount of long lived radioactive elements within our planet and fix the debated radiogenic contribution to the terrestrial heat. In addition, it will provide a direct test of the Bulk Silicate Earth model, a fundamental cosmochemical paradigm about the origin of the Earth. Unorthodox models of Earth's core (including the presence of potassium or the possibility of a giant reactor) can also be checked. This short review presents status and prospects of the field.Comment: 7 pages, 2 figures, presented at Neutrino 2004 in Pari

Nuclear physics for geo-neutrino studies

Geo-neutrino studies are based on theoretical estimates of geo-neutrino spectra. We propose a method for a direct measurement of the energy distribution of antineutrinos from decays of long-lived radioactive isotopes. We present preliminary results for the geo-neutrinos from Bi-214 decay, a process which accounts for about one half of the total geo-neutrino signal. The feeding probability of the lowest state of Bi-214 - the most important for geo-neutrino signal - is found to be p_0 = 0.177 \pm 0.004 (stat) ^{+0.003}_{-0.001} (sys), under the hypothesis of Universal Neutrino Spectrum Shape (UNSS). This value is consistent with the (indirect) estimate of the Table of Isotopes (ToI). We show that achievable larger statistics and reduction of systematics should allow to test possible distortions of the neutrino spectrum from that predicted using the UNSS hypothesis. Implications on the geo-neutrino signal are discussed.Comment: 8 pages RevTex format, 8 figures and 2 tables. Submitted to PR

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

Linguistic Miner

Abstract: In this paper we present a project titled "Linguistic Miner", designed and coordinated by Eugenio Picchi. The project arises from the availability of the PiSystem tools and the familiarity with the automatic treatment of human language. The project goal is the extraction of linguistic information from the texts and the validation of linguistic patterns. We show the objectives and the results of the project as achieved in the first months of work

Supernova Neutrinos and the Tau-Neutrino Mass

We perform an extensive investigation of the sensitivity to non-vanishing tau-neutrino mass in a large water Cherenkov detector, developing an analysis method for neutrino events originated by a supernova explosion. This approach, based on directional considerations, provides informations almost undepending on the supernova model. We analyze several theoretical models from numerical simulations and phenomenological models based on SN1987A data, and determine optimal values of the analysis parameters so as to reach the highest sensitivity to a non-vanishing tau-neutrino mass. The minimal detectable mass is generally just above the cosmologically interesting range, m ~ 100 eV, in the case of a supernova explosion near the galactic center. For the case that no positive signal is obtained, observation of a neutrino burst with Super-Kamiokande will anyhow lower the present upper bound on tau-neutrino mass to few hundred eV.Comment: 25 pages - 1 LaTeX file and 14 (E)PS figures in a tarred, gzipped, uuencoded file - figures included via EPSFIG commands - submitted to Astroparticle Physic

West Nile virus transmission. results from the integrated surveillance system in Italy, 2008 to 2015

IIn Italy a national Plan for the surveillance of imported and autochthonous human vector-borne diseases (chikungunya, dengue, Zika virus disease and West Nile virus (WNV) disease) that integrates human and veterinary (animals and vectors) surveillance, is issued and revised annually according with the observed epidemiological changes. Here we describe results of the WNV integrated veterinary and human surveillance systems in Italy from 2008 to 2015. A real time data exchange protocol is in place between the surveillance systems to rapidly identify occurrence of human and animal cases and to define and update the map of affected areas i.e. provinces during the vector activity period from June to October. WNV continues to cause severe illnesses in Italy during every transmission season, albeit cases are sporadic and the epidemiology varies by virus lineage and geographic area. The integration of surveillance activities and a multidisciplinary approach made it possible and have been fundamental in supporting implementation of and/or strengthening preventive measures aimed at reducing the risk of transmission of WNV trough blood, tissues and organ donation and to implementing further measures for vector control