ΛN−ΣNinteraction with isobar coupling and six-quark resonances

Abstract

The long-range A N -B N interaction is modeled by a configuration-space meson-exchange potential matrix coupling to channels with A and H(1385) isobars. An inner boundary condition, based on R-matrix theory, replaces form factors for short-range effects and includes the effects of free quark configurations. An excellent fit is obtained to the available data, with only the energy-independent boundary conditions as free parameters. The effect of isobar thresholds is shown to be substantial in several partial waves and is crucial to the understanding of the higher-energy A N elastic scattering data. The positions and widths of [q( ls,/> )I5s ( ls1/> ) quark exotics are predicted. PACS numbeds): 13.75. Ev, 12.40.Aa, 12.40.Qq