The role of neutrino mass observables in distinguishing neutrino mass models

Knowledge of the nature of neutrino mass is crucial in making progress in the search for beyond the Standard Model physics. The current literature contains a plethora of models attempting to explain this phenomenon, but since those models generally make similar predictions, one needs a method to distinguish them. Although no single method can provide this discriminating power, the three neutrino mass observables play an important role. These are: the sum of absolute neutrino masses (sum mi), the kinematic electron neutrino mass in beta decay (mβ) and the effective mass for neutrino-less double beta decay (left angle mee right angle). The sum mi - mβ - left angle mee right angle parameter space has been studied for two different A4 flavour symmetry models, and for models that contain a sum-rule between light neutrino masses. A simultaneous measurement of two or more observables could in principle be used to rule out certain cases. In addition, a non-standard model for neutrino mass has been analysed, where neutrino mass eigenstates can be either Dirac or Majorana (the bimodal flavour hypothesis). In this case distinct features emerge for left angle mee right angle, so that the model could be excluded by the next generation of double beta decay experiments.