Charm Radiative Decays with Neutral Mesons D^0 -> K^0(bar) pi^0 gamma, D^0 -> K^0(bar) eta (eta') gamma

摘要

The radiative decays D^0 -> K^0(bar) P^0 gamma with nonresonant K^0(bar) P^0(P^0 = pi^0, eta, eta') are considered within the framework which combinesheavy quark effective theory and the chiral Lagrangian. Due to neutral mesonsthe amplitudes do not have bremsstrahlung contributions. We assumefactorization for the weak matrix elements. Light (virtual) vector mesons arefound to give the main contribution to the decay amplitudes. The decay D^0 ->K^0(bar) pi^0 gamma is predicted to have a branching ratio of 3 x 10^(-4), withcomparable contributions from parity-conserving and parity-violating parts ofthe amplitude. The decays with eta (eta') in the final state are expected withbranching ratios of 1.1 x 10^(-5) and 0.4x10^(-7) respectively and are mainlyparity conserving.