B 0 and B s 0 decays into J / ψ f 0 ( 980 ) and J / ψ f 0 ( 500 ) and the nature of the scalar resonances

摘要

We describe the B 0 and B s 0 decays into J / ψ f 0 ( 500 ) and J / ψ f 0 ( 980 ) by taking into account the dominant process for the weak decay of B 0 and B s 0 into J / ψ and a q q ˉ component. After hadronization of this q q ˉ component into pairs of pseudoscalar mesons we obtain certain weights for the meson–meson components and allow them to interact among themselves. The final state interaction of the meson–meson components, described in terms of chiral unitary theory, gives rise to the f 0 ( 980 ) and f 0 ( 500 ) resonances and we can obtain the π + π ? invariant mass distributions after the decay of the resonances, which allows us to compare directly to the experiments. We obtain ratios of J / ψ f 0 ( 980 ) and J / ψ f 0 ( 500 ) for each of the B decays in quantitative agreement with experiment, with the f 0 ( 980 ) clearly dominant in the B s 0 decay and the f 0 ( 500 ) in the B 0 decay.