DYNAMICS OF STRONG AND RADIATIVE DECAYS OF Ds MESONS

Abstract

The positive parity scalar [Formula: see text] and axial-vector [Formula: see text] charmed strange mesons are generated by coupled-channel dynamics through the s-wave scattering of Goldstone bosons off the pseudoscalar and vector D ( D s)-meson ground states. The attraction leading to the specific masses of these states reflects the chiral symmetry breaking scale which characterizes the Weinberg-Tomozawa interaction in the chiral Lagrangian. Chiral corrections to order [Formula: see text] are calculated and found to be small. The [Formula: see text] and [Formula: see text] mesons decay either strongly into the isospin-violating π0 D s and [Formula: see text] channels or electromagnetically. We show that the π0-η and ( K 0 D +- K + D 0) mixings act constructively to generate strong widths of the order of 140 keV. The one-loop contribution to the radiative decay amplitudes of scalar and axial-vector states is calculated using the electromagnetic Lagrangian to chiral order [Formula: see text]. We show the importance of taking into account processes involving light vector mesons explicitly in the dynamics of electromagnetic decays to obtain a satisfactory description of the available data.