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. We search for doubly charmed baryons Ξcc⁺⁽⁺⁾ with the Λc⁺K^-π⁺(π⁺) and Ξc⁰π⁺(π⁺) final states. No significant signal is observed. We also search for two excited charmed strange baryons, Ξc(3055)⁺ and Ξc(3123)⁺ with the Σc⁺⁺(2455)K^- and Σc⁺⁺(2520)K^- final states. The Ξc(3055)⁺ signal is observed with a significance of 6.6 standard deviations including systematic uncertainty, while no signature of the Ξc(3123)⁺ is seen. We also study properties of the Ξc(2645)⁺ and measure a width of 2.6±0.2(stat)±0.4(syst) MeV/c², which is the first significant determination.