International Conference on Exotic Atoms and Related Topics - EXA2017

In recent years, there is a renewed interest in the dibaryons due to exclusive measurements in hadron reactions as well as the direct measurement in relativistic heavy-ion collisions. In this talk, we present the result of the first principle calculation using lattice QCD. Particularly we focus on the study for dibaryon candidates involving with the decuplet baryon: (i) the Delta-Delta system and Omega-N system with the heavy pion mass, and (ii) the Omega-Omega system with the physical pion mass. Our result of the Delta-Delta interaction is that in the 7S3 channel, only an strongly attractive interaction (no repulsive core) appears, which leads to a bound state of two-Delta's, the so-called “ABC effect”, observed as a resonance of two-nucleons in experiment by CELSIUS/WASA Collaboration. The result of the Omega-N interaction in the 5S2 channel also shows the strong attractive interaction and the deep bound state, which is expected to be probed in the heavy ion collision, and the result of the Omega-Omega interaction in the 1S0 channel at physical point shows a shallow bound state, which is similar to deuteron.