Hyperon neutrinoless double beta decays in chiral perturbation theory

We study the neutrinoless double beta decays of spin-1/2 hyperons, $B_1^- \to B_2^+ \ell^- \ell^-$ with $B_1^-\in \{Σ^-,Ξ^-\}$ and $B_2^+\in\{p,Σ^+\}$, 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.