Sterile neutrinos with non-standard interactions in β- and 0νββ-decay experiments

Charged currents are probed in low-energy precision beta-decay experiments and at high-energy colliders, both of which aim to measure or constrain signals of beyond-the-Standard-Model physics. In light of future beta-decay and LHC measurements that will further explore these non-standard interactions, we investigate what neutrinoless double-beta decay (0 nu beta beta) experiments can tell us if a nonzero signal were to be found. Using a recently developed effective-field-theory framework, we consider the effects that interactions with right-handed neutrinos have on 0 nu beta beta and discuss the range of neutrino masses that current and future 0 nu beta beta measurements can probe, assuming neutrinos are Majorana particles. For non-standard interactions at the level suggested by recently observed hints in beta decays, we show that next-generation 0 nu beta beta experiments can determine the Dirac or Majorana nature of neutrinos, for sterile neutrino masses larger than O(10) eV.