Symmetry-breaking corrections to the form factors for heavy-to-heavy B-meson at large recoil.

The present study investigates the decay of B to heavy meson using the soft collinear effective theory. By assigning different loop momenta, the factorization has been tested and it is found to be valid to all orders in the perturbation theory. It is noted that theory contains one hard collinear and two soft modes depending upon virtuality of different momenta. In the next step, symmetry-conserving relations (in heavy quark limits) to the form factors have been studied. These relations are then used to parametrize the form factors to get symmetry-breaking corrections. These symmetry-breaking corrections can be calculated using perturbative (vertex corrections) as well as nonperturbative (hard spectator interactions) QCD. It is found that in the heavy quark limit, these symmetry contributions do not contribute to the form factors that appear in physical observables for the case of B → D (D ∗) l ν l decays which are contrary to the heavy-to-light meson decays. [ABSTRACT FROM AUTHOR]