6533b856fe1ef96bd12b2cf1

RESEARCH PRODUCT

Lambda(1405) and (Lambda)over-bar(1405) in J/psi four-body decays

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We study the structure of the baryon resonances Λ(1405) and Λ¯(1405) in J/ψ four body decays J/ψ→ΣΣ¯ππ in the framework of a coupled channel chiral unitary approach. With still sufficient freedom for model parameters, the Λ(1405) and Λ¯(1405) resonances are generated by simultaneously taking the meson baryon and meson anti-baryon final state interactions into account. The πΣ (πΣ¯) invariant mass distributions peak around 1410 MeV, which favors the assertion that the Λ(1405) (Λ¯(1405)) is a superposition of the two Λ(1405) (Λ¯(1405)) states which dominantly couple to K¯N (KN¯) and πΣ (πΣ¯), respectively. We also calculate the amplitude for isospin I=1 which gives hints on a possible I=1 baryon resonance in the energy region of the Λ(1405), which up to now has not been observed.