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Abstract

In this thesis we study possibilities to distinguish different mechanisms of neutrinoless
double-β decay within a low-energy effective field theory framework. We find that the
most promising approach towards identifying the dominant contribution experimentally
is given by a measurement of half-life ratios in different isotopes. Given the experimental
accuracy, we identify 11 different groups of low-energy effective operators that
can be distinguished in this way. However, the ratios depend on currently unknown
low-energy constants that are especially important when considering short-range mechanisms.
These constants can be calculated within lattice QCD and should be obtained
in the future. Additional information about the underlying mechanism can be gained
from phase space observables as well as high-energy collider data. Finally, we studied
the impact of three different models beyond the Standard Model taken from the
literature and compared them to the standard mechanism of light neutrino exchange.