Radiative B decays provide valuable information on some poorly known CKM matrix elements |Vtb| and |Vts|. So in our letter we propose to study the flavor changing radiative B decays corresponding to the inclusive b→ sγ and b→dγ decays. In this letter we discuss the radiative flavor changing B→ K**γ, Bs→ϕ;γ and the rare Bc→D*γ decays taking into account both the Penguin as well as weak annihilation contribution and it is found that weak annihilation contribution is negligible in case of decay of mesons consisting of light spectator, i.e. for B→K**γ and Bs→ϕ;γ but in case of decay of Bc→D*γ, weak annihilation contribution is the most dominating factor. It is also interesting to note that all the B→ K**γ, Bs→ϕ;γ and Bc→ D*γ decays have almost the same decay width because they have the same type of inclusive decay process b→ s(d)γ.
Cancellation of1/mQcorrections to the inclusive decay width of a heavy quark