Search for doubly charmed baryons and study of charmed strange baryons at Belle

We report results of a study of doubly charmed baryons and charmed strange baryons. The analysis is performed using a 980 fb^–1 data sample collected with the Belle detector at the KEKB asymmetric-energy e⁺e^– collider. Here, we search for doubly charmed baryons Ξ${}_{cc}^{+(+)}$ with the Λ${}_c^{+}$K^–π⁺(π⁺) and Ξ${}_c^0$π⁺(π⁺) final states. No significant signal is observed. We also search for two excited charmed strange baryons, Ξ_c(3055)⁺ and Ξ_c(3123)⁺ with the Σ${}_c^{++}$(2455)K^– and Σ${}_c^{++}$(2520)K^– final states. Here, the Ξ_c(3055)⁺ signal is observed with a significance of 6.6 standard deviations including systematic uncertainty, while no signature of the Ξ_c(3123)⁺ is seen. We also study properties of the Ξ_c(2645)⁺ and measure a width of 2.6 ± 0.2(stat) ± 0.4(syst) MeV/c², which is the first significant determination.