Chiral EFTs for Neutrinoless Double Beta Decay

Neutrinoless double beta decay (NLDBD) is the most sensitive probe of lepton-number violation. Its discovery would be a clear signal of physics beyond the Standard Model, confirm the Majorana nature of neutrinos, and provide insight into scenarios of baryogenesis through leptogenesis. Whenever lepton-number violation arises at a scale well above the electroweak scale, it can be described by effective interactions in an effective-field theory (EFT) framework. In this talk, I will outline the necessary steps to assess the impact of these effective interactions on NLDBD half lives, focussing on the matching onto Chiral EFT at low energies. In particular, I will show why consistent renormalization of Chiral EFT requires the inclusion of a contact interaction at leading order and discuss ways to estimate the impact of this contact term. Finally, I will illustrate the constraints on the lepton-number violating interactions that can be set in this EFT framework.