Global Constraints on Neutrino Masses and Their Ordering

In this work we focus on the absolute neutrino masses and their ordering, still not known in the standard phenomenology of three massive neutrinos. Interesting constraints on the sum of neutrino masses and on mass ordering (either normal, NO or inverted, IO) can be derived from the combination of neutrino oscillation data, neutrinoless double beta (0 nu beta beta) decay experiments, and cosmological data. We derive current bounds on absolute neutrino mass observables by combining in a global data analysis the latest results from oscillation experiments, 0 nu beta beta decay limits from the KamLAND-Zen experiment, and constraints from Planck measurements and other cosmological data sets. We found that NO appears to be favored with respect to IO at the level of similar to 2 sigma, mainly by neutrino oscillation data (especially atmospheric), corroborated by cosmological data in some cases.