Clues to the nature of the Δ∗(1700) resonance from pion- and photon-induced reactions

We make a study of the π−p→K0π0Λ, π+p→K+π+Λ, K+K¯0p, K+π+Σ0, K+π0Σ+, and ηπ+p reactions, in which the basic dynamics is given by the excitation of the Δ∗(1700) resonance which subsequently decays into KΣ∗(1385) or Δ(1232)η. In a similar way we also study the γp→K0π+Λ, K+π−Σ+, K+π+Σ−, K0π0Σ+, and ηπ0p related reactions. The cross sections are proportional to the square of the coupling of Δ∗(1700) to Σ∗K (Δη) for which there is no experimental information but which is provided in the context of coupled channels chiral unitary theory where the Δ∗(1700) is dynamically generated. Within present theoretical and experimental uncertainties one can claim a global qualitative agreement between theory and experiment. We provide a list of items which need to be improved in order to make further progress along these lines.