Study of X(1812) as a $(K^*\bar K^*)$ Molecular State

Abstract

We investigate the decay and the production mechanism of the resonance X(1812) recently observed in the $\jp\to\gamma X(1812), X(1812)\to\omega\phi$ at BESII. The decay widths of $X(1812)\to\eta\eta'$,$ \eta\eta$,$ \omega\phi$,$ K^+K^-$,$ \rho^+\rho^-$, $ \omega\omega$,$ K^{*+}K^{*-}$ and $\pi^+\pi^-$ are evaluated based on the scenario of the X(1812) as a candidate of $(\ksks)$ molecule. It turns out that the quark exchange mechanism plays an important role in the understanding of the large decay width for the $X(1812)\to\omega\phi$. It is also found that the decay widths for $X(1812)\to\eta\eta'$ and $\eta\eta$ are enhanced by the quark exchange mechanism. These channels are suggested to be the tools to test the molecular scenario in experiment. The branching fraction of $Br(X\to\omega\phi)$ is evaluated to be about 4.60%. Searches for additional evidence about the X(1812) in $\jp$ radiative decays are reviewed. In the molecular scenario, the X(1812) production rate is also evaluated to be $\Gamma(\jp\to\gamma X)/\Gamma(\jp\to\gamma K^{*+}K^{*-})=2.13^{+7.41}_{-1.85}$, which is close to the measured value $2.83\pm0.92$.