Radiative and isospin-violating decays of Ds-mesons in the hadrogenesis conjecture

The masses and decays of the scalar (2317) and axial-vector charmed strange mesons are calculated consistently in the hadrogenesis conjecture. These mesons decay either strongly into the isospin-violating π0Ds and channels or electromagnetically. They are generated by coupled-channel dynamics based on the leading order chiral Lagrangian. The effect of chiral corrections to chiral order is investigated. We show that taking into account large-Nc relations to determine the strength of these correction terms implies a measurable signal for an exotic axial-vector state in the ηD∗ invariant mass distribution. The one-loop contribution to the electromagnetic decay amplitudes of scalar and axial-vector states is calculated. The Lagrangian describing electromagnetic interactions is obtained by gauging the chiral Lagrangian for hadronic interactions and adding gauge-invariant correction terms to chiral order . In addition the role of light vector meson degrees of freedom is explored. We confront our results with measured branching ratios. Once the light vector mesons are included, a natural explanation of all radiative decay parameters is achieved.