QCD Light-Cone Sum Rule Estimate of Charming Penguin Contributions in B -> pi pi

Abstract

Employing the QCD light-cone sum rule approach we calculate the B -> pi pi 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(alpha_s) with respect to the factorizable B -> pi pi amplitude. The effects of soft gluons are suppressed at least by O(alpha_s m_b^{-2}). Our result indicates that sizable nonperturbative effects generated by charming penguins at finite m_b are absent. The same is valid for the penguin contractions of the current-current operators with light quarks.

Comments: 12 pages, 5 figures included ; minor corrections