Rescattering effects in charmless decays

Final-state interaction effects in charmless decays are studied. Our main results are as follows: (i) Theoretical results are in agreement with data in the presence of FSI. (ii) The and π0π0 decay rates are suppressed and enhanced respectively by FSI. (iii) The FSI has large impact on direct CP asymmetries (A) of many modes. (iv) The deviation(ΔA) between and A(B−→K−π0) can be understood in the FSI approach. (v) Sizable and complex color-suppressed tree amplitudes, which are crucial for the large π0π0 rate and ΔA, are generated through exchange rescattering. (vi) The B−→π−π0 direct CP violation is very small and is not affected by FSI. (vii) Several decay rates are enhanced. (viii) Time-dependent CP asymmetries S in decays are studied. The is very small (⩽1%). We found that the asymmetries |S| for , ηη′ and η′η′ decays are all below 0.06.