Oscillating Neutrino Mass States and Double Beta Decay

Neutrino oscillation is an experimentally established phenomenon by which neutrinos undergo flavor transformations periodically as they propagate large enough distances. Oscillation experiments provide information about the mass-squared differences and the leptonic mixing angles, but they are insensitive to the absolute mass scale for the neutrinos. As neutrino oscillations give no information about the absolute value of the neutrino mass squared eigenvalues, hence, there are various possibilities of neutrino hierarchy spectrums consistent with solar and atmospheric neutrino oscillation data. In this paper, we have attempted to present a picture of neutrino mass spectrum in the case of normal, inverted and almost degenerate hierarchy of neutrino masses by taking some specific choice of effective mass of electron neutrino related to 0 νββ decay. We find neutrino mass eigenvalues m_i in different neutrino mass spectrum and also calculate percentage change in mass eigenvalues by taking uncertainties in the best fit neutrino oscillation parameters. The normal and inverted mass ordering of neutrino masses in context of future double–beta–decay experiments is discussed at the end.