Tensor-meson dominance and glueball candidate theta (1720).

Abstract

By postulating naive tensor-meson dominance in the energy-momentum-tensor ${\ensuremath{\theta}}_{\ensuremath{\mu}\ensuremath{\nu}}$ couplings, we find that, in addition to f and f', another tensor meson is needed to explain the ratio of \ensuremath{\Gamma}(f'\ensuremath{\rightarrow}KK\ifmmode\bar\else\textasciimacron\fi{})/\ensuremath{\Gamma}(f\ensuremath{\rightarrow}\ensuremath{\pi}\ensuremath{\pi}). Considering \ensuremath{\theta}(1720), the tensor-glueball candidate, as this meson we obtain the matrix element 〈\ensuremath{\theta}\ensuremath{\Vert}${\ensuremath{\theta}}_{\ensuremath{\mu}\ensuremath{\nu}}$\ensuremath{\Vert}0〉. The branching ratio of \ensuremath{\theta}(1720) in J/\ensuremath{\psi} radiative decay is thus calculated which agrees very well with the observed experimental branching ratio of \ensuremath{\theta}(1720) which decays to KK\ifmmode\bar\else\textasciimacron\fi{}, \ensuremath{\eta}\ensuremath{\eta}, and \ensuremath{\pi}\ensuremath{\pi}.