Doubly heavy baryons with chiral partner structure

The spectrum and dominant strong decay properties of the doubly heavy baryons are revisited by using a chiral effective model with the chiral partner structure. By regarding the doubly heavy baryons in the ground states and light angular momentum, j(l) = 1/2, sector of the first orbitally excited states as chiral partners, we estimate their mass splitting arising from the spontaneous breaking of chiral symmetry to be about 430 MeV for baryons including an unflavored light quark and about 350 MeV for that including a strange quark. We point out that, similar to the heavy-light meson sector, the intermultiplet decay from a baryon with negative parity to its chiral partner and a pion is determined by the mass splitting through the generalized Goldberger-Treiman relation. Furthermore, the isospin-violating decay of the Omega(cc) baryon, ((1/2)(-), (3/2)(-))(s) -> ((1/2)(+), (3/2)(+))(s) + pi(0), through the eta-pi(0) mixing is the dominant decay channel of the doubly heavy baryons including a strange quark. (C) 2015 The Authors. Published by Elsevier B.V.