Phenomenological description of the D s 0 * ( 2317 ) → D s π 0 decay

Source abstract

For coupled channels D 0 K + , D + K 0 , D s + η , and D s + π 0 , the S -wave scattering amplitudes are constructed taking into account the mixing of the isoscalar resonance D s 0 * ( 2317 ) + with nonresonance amplitudes with isospin I = 1 . The phenomenological approach we use allows us to quite simply clear up the general structure of the D s 0 * ( 2317 ) + → D s + π 0 decay amplitude violating isospin. We show that the phase of this amplitude coincides with the phase of the nonresonanct D s + π 0 scattering amplitude in agreement with the Watson theorem. Its modulus squared, as it should be, determines the width of the resonance peak in the D s + π 0 channel. Taking into account the π 0 − η mixing in internal lines up to the second order inclusively ensures that the unitarity condition is fulfilled. The presented analysis complements the description of the D s 0 * ( 2317 ) + → D s + π 0 decay based on the coupled channel unitarized chiral perturbation theory. The numerical estimates obtained by us for the D s 0 * ( 2317 ) + → D s + π 0 decay width do not contradict those available in the literature.