Radiative Decay Bc → Ds*γ in the Technicolor with a Massless Scalar Doublet Model

Applying perturbative QCD, we study the process Bc → Dsγ in the technicolor with a massless scalar doublet model (TCMLSM). There are mainly two mechanisms contributing to the Bc → D*sγ process. One proceeds through the short distance b → sγ transition and the other through weak annihilation accompanied by a photon emission.We find that, compared with the standard model, the modification of Bc → D*sγ from πρ (the physical pions in the TCMLSM) is so small that can be neglected for the allowed mass ofπρ. The weak-annihilation contribution is found to be about one order larger than that of the electromagnetic penguin diagrams.