Use of B→J/ψ f0 decays to discern the qq or tetraquark nature of scalar mesons.

We consider the relative decay rates of B(0) and Bs(0) mesons into a J/ψ plus a light scalar meson, either the f0(500) (σ) or the f0(980). We show that it is possible to distinguish between the quark content of the scalars being quark-antiquark or tetraquark by measuring specific ratios of decay rates. Using current data we determine the ratio of form factors in Bs(0)→J/ψf0(980) with respect to B(0)→J/ψf0(500) decays to be 0.99(-0.04)(+0.13) at a four-momentum transfer squared equal to the mass of the J/ψ meson squared. In the case where these light mesons are considered to be quark-antiquark states, we give a determination of the mixing angle between strange and light quark states of less than 29° at 90% confidence level. We also discuss the use of a similar ratio to investigate the structure of other isospin singlet states.