Abstract
We point out that the data have seriously constrained the possibility of resolving the puzzle from the large observed branching ratio in the available theoretical approaches. The next-to-leading-order (NLO) contributions from the vertex corrections, the quark loops, and the magnetic penguin evaluated in the perturbative QCD (PQCD) approach have saturated the experimental upper bound of the branching ratio and do not help. The NLO PQCD predictions for the and branching ratios are consistent with the data. The inclusion of the NLO jet function from the soft-collinear effective theory into the QCD-improved factorization approach, though enhancing the branching ratio sufficiently, overshoots the bound of the branching ratio and deteriorates the predictions for the and direct asymmetries.
- Received 5 March 2006
DOI:https://doi.org/10.1103/PhysRevD.73.114014
©2006 American Physical Society