Motivated by recent measurements, we investigate B→,K decay modes in the framework of QCD improved factorization, which was recently proposed by Beneke et al. We find that all the measured branching ratios are well accommodated in the reasonable parameter space except for B→K 0 0 . We also discuss in detail the strong penguin contributions and the O(␣ s ) corrections to the chirally enhanced terms. We find that the weak phase ␥ lies in the region 120°Ͻ␥Ͻ240°, which is mainly constrained by B→ Ϫ ϩ .

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We calculate the decay rate Γ(B → X s γγ) via intermediate psuedoscalar charmonium η c . This process is thought to be the main long-distance contribution which dominates the corresponding inclusive rare B decay. We point out that once the momentum dependence of η c → γγ conversion strength, due to off-shellness of the intermediate η c , is taken into account, the rate of this decay mode is reduced. The change in differential decay rate in region of spectrum immediately below m ηc is more significant. On the other hand, we point out that the unexpectedly large branching ratio for B → X s η ′ which is recently observed by CLEO could indicate a potentially larger long-distance contribution via η ′ resonance.