Studies of charmed strange baryons in the Λ D final state at Belle

Abstract

We report the discovery of Ξ c ( 3055 ) 0 , observed by its decay into the final-state Λ D 0 , and present the first observation and evidence of the decays of Ξ c ( 3055 ) + and Ξ c ( 3080 ) + into Λ D + . We also perform a combined analysis of the Λ D + with the Σ + + c K − and Σ * + + c K − decay modes to measure the ratios of branching fractions, masses and widths with improved accuracy. We measure the ratios of branching fractions B ( Ξ c ( 3055 ) + → Λ D + ) / B ( Ξ c ( 3055 ) + → Σ + + c K − ) = 5.09 ± 1.01 ± 0.76 , B ( Ξ c ( 3080 ) + → Λ D + ) / B ( Ξ c ( 3080 ) + → Σ + + c K − ) = 1.29 ± 0.30 ± 0.15 , and B ( Ξ c ( 3080 ) + → Σ * + + c K − ) / B ( Ξ c ( 3080 ) + → Σ + + c K − ) = 1.07 ± 0.27 ± 0.04 , where the uncertainties are statistical and systematic. The analysis is performed using a 980

fb − 1 data sample collected with the Belle detector at the KEKB asymmetric-energy e + e − collider.