ar X iv : h ep - p h / 04 04 14 9 v 2 3 0 Ju n 20 04 B → Kπ Decays with 1 / m b Corrections in QCD Factorization

A careful investigation of 1/mb power suppressed effects is crucial for enhancing predictive power of the QCD factorization approach to charmless B decays. It is instructive to systematically investigate the 1/mb effects from soft and hard gluon exchanges, in addition to annihilation topology in the charmless B decays. In this work we try to give a systematic discussion on impact of such soft and hard exchanges on the penguin-dominated B → Kπ decays within the framework of the light-cone QCD sum rules (LCSR). For the weak phase γ(= ImV ∗ ub) ranging from 40 ◦ to 80, we find that because of the annihilation and soft and hard exchanges a numerical increase of (20 − 30)% is expected in the branching ratios up to O(1/mb) corrections. In a quantitative analysis, the resultant soft and hard effects are less important than the annihilation contributions and amount only to a level of a few percents. Possible sources of uncertainties are discussed in some details. PACS number(s): 12.38.Lg, 11.55.Hx, 13.20.He Email:[email protected] Mailing address