Final State Interaction Effects in B+→J/ψ π+ Decay

In this research the exclusive decay of B^+?J/? ?^+ is calculated by QCD factorization (QCDF) method and final state interaction (FSI). First, the B^+?J/? ?^+ decay is calculated via QCDF method. The result that is found by using the QCDF method is less than the experimental result. So FSI is considered to solve the B^+?J/? ?^+decay. For this decay, D^+ D ?^(0^* ) via the exchange of D^- and D^(-^* ) mesons are chosen for the intermediate state. The above intermediate state is calculated by using the QCDF method. In the FSI effects, the results of our calculations depend on ? as the phenomenological parameter. The range of this parameter is selected from 2 to 3. It is found that if ?=2.8 is selected, the numbers of the branching ratio are placed in the experimental range. The experimental branching ratio of B^+?J/? ?^+ decay is 4.9×?10?^(-5) and our results calculated by QCDF and FSI are 0.56×?10?^(-5) and 3.9 ×?10?^(-5) respectively.