Hyperon neutrinoless double beta decays in chiral perturbation theory

We study the neutrinoless double beta decays of spin-1/2 hyperons, $B_1^{-}\to B_2^{+}{\mathrm{\ell }}^{-}{\mathrm{\ell }}^{-}$ with $B_1^{-}\in \{{\mathrm{\Sigma }}^{-},{\mathrm{\Xi }}^{-}\}$ and $B_2^{+}\in \{p,{\mathrm{\Sigma }}^{+}\}$, which violate lepton number by two units. The decay amplitudes are computed within covariant baryon chiral perturbation theory at the one-loop level. Dalitz plots of the squared amplitude for six physical decay processes are presented in this proceeding, while a detailed numerical analysis will be presented in a forthcoming publication.