Two-loop non-leptonic penguin amplitude in QCD factorization

A Two-Loop Four-Gluon Helicity Amplitude in QCD

We present the two-loop pure gauge contribution to the gluon-gluon scattering amplitude with maximal helicity violation. Our construction of the amplitude does not rely directly on Feynman diagrams, but instead uses its analytic properties in 4 − 2 dimensions. We evaluate the loop integrals appearing in the amplitude through O( ) in terms of polylogarithms.

Recent results from the QCD factorization approach to non - leptonic B decays ∗

Spectator scattering at NLO in non-leptonic B decays: Leading penguin amplitudes

We complete the computation of the 1-loop (αs) corrections to hard spectator scattering in non-leptonic B decays at leading power in Λ/mb by evaluating the penguin amplitudes. This extends the knowledge of these next-to-next-to-leadingorder contributions in the QCD factorization formula for B decays to a much wider class of final states, including all pseudoscalar-pseudoscalar, pseudoscalar-vec...

Factorization in Non-leptonic Decays of Heavy Mesons

We propose a QCD-based model for calculation of the non-perturbative corrections to the factorization approximation in the decays of heavy mesons. In the framework of the model, factorization in pseudoscalar transitions holds exactly at the leading order leaving the opportunity to calculate non-leading corrections consistently.

Factorization of the Two Loop Four-Particle Amplitude in Superstring Theory Revisited

We study in detail the factorization of the newly obtained two-loop four-particle amplitude in superstring theory. In particular some missing factors from the scalar correlators are obtained correctly, in comparing with a previous study of the factorization in two-loop superstring theory. Some details for the calculation of the factorization of the kinematic factor are also presented. E-mail: x...