Charmed baryons studied by pion emission decays

We investigate the decays of the charmed baryons aiming at the systematic understanding of hadron internal structures based on the quark model by paying attention to heavy quark symmetry.  We evaluate the decay widths from the pion emission for the known excited states, Λ_c(2595), Λ_c(2625), Λ_c(2765), Λ_c(2880), and Λ_c(2940).  The decay properties of the lower excited charmed baryons are well explained, and several important predictions for higher excited baryons are given.  We emphasize the importance of the branching ratios of Σ_c π and Σ^*_c  π channels for the study of the nature of higher excited Λ_c baryons.   Especially, we find that a small branching ratio of Λ_c(2880)  might imply that a specific quark configuration dominates the  Λc(2880) baryons.