Final state interaction in B0 → J/ψπ+π− decay

Abstract

In this research, we study three body non-leptonic decay B0 → J/ψπ+π− by introducing a two-meson distribution amplitude for the π+π− pair, such that the analysis is simplified into the one for two body decay. By applying the final state interaction, the branching ratio of resonance decay is calculated by generalized factorization and improved quantum chromodynamics factorization (QCDF). Our results are (2.96 ± 0.06) × 10−5 and (4.30 ± 0.02) × 10−5 in these approximations, respectively. In QCDF at an energy scale μ = 2mb, the obtained branching ratio is in agreement with available experimental data: (4.6 ± 0.9) × 10−5.