New spectrum of negative-parity doubly charmed baryons: Possibility of two quasistable states

The discovery of Xi(++)(cc) by the LHCb Collaboration triggers predictions of more doubly charmed baryons. By taking into account both the P-wave excitations between the two charm quarks and the scattering of light pseudoscalar mesons off the ground state doubly charmed baryons, a set of negative-parity spin-1/2 doubly charmed baryons are predicted already from a unitarized version of leading order chiral perturbation theory. Moreover, employing heavy antiquark-diquark symmetry, the relevant low-energy constants in the next-to-leading order are connected with those describing light pseudoscalar mesons scattering off charmed mesons, which have been well determined from lattice calculations and experimental data. Our calculations result in a spectrum richer than that of heavy mesons. We find two very narrow JP = 1/2(-) Omega(P)(cc), which very likely decay into Omega(cc)pi(0) breaking isospin symmetry. In the isospin-1/2 Xi(P)(cc) sector, three states are predicted to exist below 4.2 GeV with the lowest one being narrow and the other two rather broad. We suggest to search for the Xi(P)(cc) states in the Xi(++)(cc)pi(-) mode. Searching for them and their analogues are helpful to establish the hadron spectrum.