2002/05/14 by Naoyuki Haba, Noboru Nakamura, Haba, Naoyuki +4
Physics and Astronomy · #Dark Matter and Cosmic Phenomena #Neutrino Physics Research #Particle physics theoretical and experimental studies #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/0205141
13 pages, 4 figures, LaTeX
arxiv created 2002/09/25 · arxiv updated 2009/11/30
Recently the evidence of the neutrinoless double β (0νββ) decay has been announced. This means that neutrinos are Majorana particles and their mass hierarchy is forced to inverted mass hierarchy (Type B) or degenerate mass (Type C) patterns in the diagonal basis of charged lepton mass matrix. We estimate the magnitude of 0νββ decay in the degenerate neutrinos including the cosmological constraint of neutrino dark matter, since the inverted mass hierarchy pattern always satisfies the cosmological constraint. The absolute value of neutrino mass is constrained by 0νββ experiment or cosmology depending on the relative signs (Majorana CP phases) of neutrino masses.