TTP01-30 Counting contact terms in $B \to V \gamma$ decays
TTP01-30 Counting contact terms in $B \to V \gamma$ decays
TTP01-30 Counting contact terms in $B \to V \gamma$ decays
We clarify the origin and cancellation of contact terms in the weak
annihilation amplitudes contributing to $B\to V \gamma$.
It is demonstrated that the photon emission from the final-state quarks
vanishes in the chiral limit of massless quarks. The contact terms in
the QCD light-cone sum rule evaluation of the weak annihilation
amplitudes are also discussed.
Alexander Khodjamirian and Daniel Wyler
in a volume “From Integrable Models to Gauge Theories”, in honor of Sergei Matinyan, edited by V. G. Gurzadyan and A. G. Sedrakian, World Scientific, Singapore, 2002