Ju n 20 07 A possible explanation why the Θ + is seen in some experiments and not in others

To understand the whole set of positive and null data on the Θ(1530)-production, we suggest the hypothesis that multiquark hadrons are mainly generated from many-quark states, which emerge either as short-term hadron fluctuations, or as hadron remnants in hard processes. This approach allows us to describe both non-observation of the Θ in current null experiments and peculiar features of its production in positive experiments. Further, we are able to propose new experiments that might be decisive for the problem of the Θ existence. Distributions of the Θ in such experiments can give important information both on higher Fock components of conventional hadrons and about structure and hadronization properties of hadron remnants produced in hard processes. We also explain that description of multiquark hadrons may require a modified form of the constituent quark model, with quark masses and couplings being intermediate between their values for the familiar constituent quarks and the current ones. PACS: 12., 12.39.-x, 12.39.Mk