Use of B->J/\psi f0 decays to discern the q anti-q or tetraquark nature of scalar mesons

Abstract

We consider the relative decay rates of B0 and Bs mesons into a J\psi\ plus a light scalar meson either the f0(500) (\sigma) 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->J\psi f0(980) with respect to B0->J\psi f0(500) decays to be 1.02(+0.14, -0.04) at a four-momentum transfer squared equal to the mass of the J\psi\ 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 28 degrees at 90% confidence level. We also discuss the use of a similar ratio to investigate the structure of other isospin singlet states.

Comments: 7 pages 2 figures, submitted to Physical Review Letters, v2, v3 & v4 added ref fixed typos