A narrow quasi-bound state of the DNN system

Abstract

Abstract We have investigated a charmed system of DNN (composed of two nucleons and a D meson) by a complementary study with a variational calculation and a Faddeev calculation with fixed-center approximation (Faddeev-FCA). In the present study, we employ a DN potential based on a vector–meson exchange picture in which a resonant Λ c ( 2595 ) is dynamically generated as a DN quasi-bound state, similarly to the Λ ( 1405 ) as a K ¯ N one in the strange sector. As a result of the study of variational calculation with an effective DN potential and three kinds of NN potentials, the D N N ( J π = 0 − , I = 1 / 2 ) is found to be a narrow quasi-bound state below Λ c ( 2595 ) N threshold: total binding energy ∼ 225 MeV and mesonic decay width ∼ 25 MeV . On the other hand, the J π = 1 − state is considered to be a scattering state of Λ c ( 2595 ) and a nucleon. These results are essentially supported by the Faddeev-FCA calculation. By the analysis of the variational wave function, we have found a unique structure in the D N N ( J π = 0 − , I = 1 / 2 ) such that the D meson stays around the center of the total system due to the heaviness of the D meson.