Measurement of branching ratio of 
decay is a critical test for consistency of different parameters of Cabbibo-Kabayashi-Maskawa matrix, and Standard Model in common.
This is one of the best probes to understand the origin of the CP violation because:
- The hadron matrix element is extracted from the experimental data of
measurement. - Indirect CP violation is highly suppressed (10-4).
- There are not significant QCD corrections.
- The relative probability of the decay is directly connected with CP-violated mixing matrix components. This allows the Standard Model to be checked with an exclusive accuracy.
Unitary triangle.
