Neutrino mass models: new classification and modelindependent upper limits on their scale
Abstract
We propose a modelindependent framework to classify and study neutrino mass models and their phenomenology. The idea is to introduce one particle beyond the Standard Model which couples to leptons and carries lepton number together with an operator which violates lepton number by two units and contains this particle. This allows to study processes which do not violate lepton number, while still working with an effective field theory. The contribution to neutrino masses translates to a robust upper bound on the mass of the new particle. We compare it to the stronger but less robust upper bound from Higgs naturalness and discuss several lower bounds. Our framework allows to classify neutrino mass models in just 20 categories, further reduced to 14 once nucleon decay limits are taken into account, and possibly to 9 if also Higgs naturalness considerations and direct searches are considered.
 Publication:

European Physical Journal C
 Pub Date:
 November 2019
 DOI:
 10.1140/epjc/s1005201974651
 arXiv:
 arXiv:1903.10552
 Bibcode:
 2019EPJC...79..938H
 Keywords:

 High Energy Physics  Phenomenology
 EPrint:
 10 pages, 1 table, 1 figure