Global constraints on absolute neutrino masses and their ordering
  Within the standard three-neutrino framework, the absolute neutrino masses
and their ordering (either normal, NO, or inverted, IO) are currently unknown.
However, the combination of current data coming from oscillation experiments,
neutrinoless double beta decay searches, and cosmological surveys, can provide
interesting constraints for such unknowns in the sub-eV mass range, down to
O(0.1) eV in some cases. We discuss current limits on absolute neutrino mass
observables by performing a global data analysis, that includes the latest
results from oscillation experiments, neutrinoless double beta decay bounds
from the KamLAND-Zen experiment, and constraints from representative
combinations of Planck measurements and other cosmological data sets. In
general, NO appears to be somewhat favored with respect to IO at the level of
~2 sigma, mainly by neutrino oscillation data (especially atmospheric),
corroborated by cosmological data in some cases. Detailed constraints are
obtained via the chi^2 method, by expanding the parameter space either around
separate minima in NO and IO, or around the absolute minimum in any ordering.
Implications for upcoming oscillation and non-oscillation neutrino experiments,
including beta-decay searches, are also discussed.
