Relativistic three-body calculations of a Y = 1, I=32, J^P = ^{2 +} πΛN-πσN dibaryon

The πΛ. N-πσ. N coupled-channel system with quantum numbers (Y, I, J^P)=(1, 32, 2⁺) is studied in a relativistic three-body model, using two-body separable interactions in the dominant p-wave pion-baryon and S13 YN channels. Three-body equations are solved in the complex energy plane to search for quasibound state and resonance poles, producing a robust narrow πΛN resonance about 10-20 MeV below the πσN threshold. Viewed as a dibaryon, it is a S25 quasibound state consisting of σ(1385). N and δ(1232). Y components. Comparison is made between the present relativistic model calculation and a previous, outdated nonrelativistic calculation which resulted in a πΛN bound state. Effects of adding a K̄NN channel are studied and found insignificant. Possible production and decay reactions of this (Y,I,JP)=(1,32,2+) dibaryon are discussed.