Charm radiative decays with neutral mesons D0→K̄0π0γ, D0→K̄0η(η′)γ

The radiative decays D0→K̄0P0γ with nonresonant K̄0P0 (P0=π0,η,η′) are considered within the framework which combines heavy quark effective theory and the chiral Lagrangian. Due to neutral mesons the amplitudes do not have bremsstrahlung contributions. We assume factorization for the weak matrix elements. Light (virtual) vector mesons are found to give the main contribution to the decay amplitudes. The decay D0→K̄0π0γ is predicted to have a branching ratio of 3×10−4, with comparable contributions from parity-conserving and parity-violating parts of the amplitude. The decays with η(η′) in the final state are expected with branching ratios of 1.1×10−5 and 0.4×10−7, respectively, and are mainly parity conserving.