Weak decays of doubly heavy baryons: SU(3) analysis

Motivated by the recent LHCb observation of doubly charmed baryon (++)(Xi cc) in the Lambda K-+(c)-pi(+)pi(+) final state, we analyze the weak decays of doubly heavy baryons Xi(cc), Omega(cc), Xi(bc), Omega(bc), Xi(bb) and Omega(bb) under the flavor SU(3) symmetry. The decay amplitudes for various semileptonic and nonleptonic decays are parametrized in terms of a few SU(3) irreducible amplitudes. We find a number of relations or sum rules between decay widths and CP asymmetries, which can be examined in future measurements at experimental facilities like LHC, Belle II and CEPC. Moreover, once a few decay branching fractions have been measured in the future, some of these relations may provide hints for exploration of new decay modes.