QCD light-cone sum rule estimate of charming penguin contributions in B→ππ

Abstract

Employing the QCD light-cone sum rule approach we calculate the B→ππ hadronic matrix element of the current–current operator with c quarks in the penguin topology (“charming penguin”). The dominant contribution to the sum rule is due to the c-quark loop at short distances and is of O(αs) with respect to the factorizable B→ππ amplitude. The effects of soft gluons are suppressed at least by O(αsmb−2). Our result indicates that sizable nonperturbative effects generated by charming penguins at finite mb are absent. The same is valid for the penguin contractions of the current–current operators with light quarks.