Study light scalar meson property from heavy meson decays

Abstract

In the SU(3) symmetry limit, the ratio $R\equiv\frac{{\cal B}(D^+\to f_0l^+ν)+ {\cal B}(D^+\to σl^+ν)}{{\cal B}(D^+\to a_0^0l^+ν)}$ is equal to 1 if the scalar mesons are $\bar qq$ states, while it is 3 if these mesons are tentraquark states. This ratio provides a model-independent way to distinguish the descriptions for light scalar mesons . It also applies to the $B^-\to Sl^-\barν$ and $\bar B^0\to J/ψ(η_c) S$ decays. The SU(3) symmetry breaking effect is found to be under control, which will not spoil our method. The branching fractions of the $D^+\to S l^+ν$, $B^-\to S l^-\barν$ and $\bar B^0\to J/ψ(η_c) S$ decays roughly have the order $10^{-4}$, $10^{-5}$ and $10^{-6}$, respectively. The B factory experiments and ongoing BEPC-II experiments are able to measure these channels and accordingly to provide the detailed information of the scalar meson inner structure.