and the corresponding limits for the long-range part can be easily derived as well, using the recipes described below and in the appendix.

Our paper is not the first work attempting a systematic analysis of the $d=9$ [$0\nu\beta\beta$ ]{}decay operator, relevant earlier papers include [@Pas:1999fc; @Pas:2000vn; @Babu:2001ex; @deGouvea:2007xp; @delAguila:2012nu]. The authors of [@Pas:1999fc; @Pas:2000vn] worked out a general Lorentz-invariant parametrisation for the [$0\nu\beta\beta$ ]{}decay rate. This approach is motivated from the nuclear physics point of view of [$0\nu\beta\beta$ ]{}decay. At low energies, adequate for [$0\nu\beta\beta$ ]{}decay studies, any of the [$0\nu\beta\beta$ ]{}diagrams in which heavy mediation fields are inserted among the six fermions $\bar{u}\bar{u} dd \bar{e} \bar{e}$ will be reduced to a finite set of combinations of the hadronic and the leptonic currents corresponding to a basic set of nuclear matrix elements. This approach leaves the LNV parameters in the [$0\nu\beta\beta$ ]{}decay rate unspecified, and our current work can be understood as providing a (tree-level) complete list of all possible ultraviolet completions (“models”) for [$0\nu\beta\beta$ ]{}decay. As expected, at low energies any information on the particle models is reduced then to one (or a combination of more than one) of the coefficients $\epsilon_i$ of the effective [$0\nu\beta\beta$ ]{}currents presented in 