Light-neutrino mass spectrum, nuclear matrix elements, and the observability of neutrinoless ββ decay

Parameters which describe neutrino flavor oscillations and neutrino mixing mechanisms, obtained from the analysis of the Sudbury Neutrino Observatory (SNO), Super-Kamiokande (SK), CHOOZ, KamLAND and WMAP data, are used to calculate upper limits of the effective neutrino mass (m(nu)) relevant for the neutrinoless double-beta decay (0nubetabeta). The observability of planned 0nubetabeta experiments, and the present status of the decay of Ge-76 are discussed within different light-neutrino mass spectra and by presenting a systematics on the available nuclear matrix elements. (C) 2003 Elsevier B.V. All rights reserved.