Geo-neutrinos: an approach to their uncertainties and correlations

Abstract

Geo-neutrinos emitted by heat-producing elements (U, Th and K) represent a unique probe of the Earth interior. The characterization of their fluxes is subject, however, to large and correlated uncertainties. In this context, we propose an approach in terms of covariance matrices, motivated by the fact that all the relevant geo-ν observables and constraints can be expressed as linear functions of the U, Th and K abundances in the Earth's reservoirs. We briefly discuss the construction of a tentative ‘geo-ν source model’ (GNSM) for the U, Th and K abundances in the main Earth reservoirs, based on geophysical and geochemical data and models (when available) and on supplementary assumptions (when needed). We use then the GNSM to make predictions about several experiments (‘forward approach’), and to show how future data can constrain the error matrix of the model itself (‘backward approach’). The method may provide a useful statistical framework for evaluating the impact and the consistency of prospective geo-ν measurements and Earth models.