Unitarized Chiral Dynamics in Three-body systems

We have used unitary chiral dynamics in a coupled channel approach to solve the Faddeev equations for different two meson-one baryon and three meson systems. We have found many resonances in the strangeness S = 0,−1 and 1 sector which can be identified with many of the 1/2+ states listed by the Particle Data Group (PDG). In concrete, in the strangeness S = 0 sector, we have studied the ππN system and its coupled channels and we report three N states, N(1710), N(1920), N(2100) and one ∆ resonance, ∆(1910), with JP = 1/2+. The state at 1920 MeV is not listed by the PDG and it was predicted by the authors of [1]. In the strangeness S =−1 sector, we have solved the equations for the πK̄N system and its coupled channels and we find four Σ’s and two Λ’s, in the 1500−1800 MeV region, as two meson-one baryon S-wave 1/2 resonances, which correspond to all the low-lying S = −1 and JP = 1/2+ states listed by the PDG. We have investigated the possibility to generate dynamically states with S = 1 in the πKN system and we have observed a broad structure around 1700 MeV with a width of 200 MeV which could be observed in reactions involving the πKN channel in the final state interaction. We have also studied three meson systems like φKK̄, φππ and J/ψKK̄, J/ψππ and found, in the first one, dynamical generation of a resonance with φ f0(980) structure, JPC = 1 and a mass around 2150 MeV, which can be identified with the X(2175) resonance and, for the second one, a peak close to 4200 MeV which can be identified with the Y (4260) state observed by different experimental groups