Abstract:
We investigate the factorizability of the decay amplitude W+ → Bγ at tree
level and with one loop QCD corrections. It was found that working in the
heavy quark limit allows these amplitudes to be factorized as this limit sets
the tone for the kinematical hierarchy of this process which is
mW ∼ mb >> ΛQCD. In light of this one can employ the Factorization
Theorem of Heavy Quark Effective Theory to express each amplitude as a
convolution of a hard perturbative part, namely the Hard Kernel and a non perturbative part, the LCDA.
The decay amplitude can be decomposed in terms of two scalar form factors
FV and FA which can be shown to be equal up-to one loop level. They can be
explicitly calculated using the Hard Kernel and a model dependent LCDA.
