Abstract :
The newest progress on the study of the strangeness in the proton and in the lowest negative parity nucleon excited state N∗(1535) is reviewed. Implications on the internal quark structure of the proton, N∗(1535) and other baryons are discussed. The diquark cluster picture for the 5-quark components in baryons gives a natural explanation not only to the empirical indications for a positive strangeness magnetic moment μs and positive strangeness radius of the proton but also the longstanding mass-reverse problem of N∗(1535), N∗(1440) and Λ∗(1405) resonances as well as the unusual decay pattern of the N∗(1535) resonance. Evidence for possible existence of N∗′(1535)s1/2−SU(3) nonet partners in this picture is pointed out, and suggestion is made to search for these 1/2− hyperon excited states under the well known Σ∗(1385), Λ∗(1520) and Ξ∗(1530) peaks in various reactions.
