Flux-Tube Ring and Glueball Properties in the Dual Ginzburg-Landau Theory

An intuitive approach to the glueball using the flux-tube ring solution in the dual Ginzburg-Landau theory is presented. The description of the flux-tube ring as the relativistic closed string with the effective string tension enables us to write the hamiltonian of the flux-tube ring using the Nambu-Goto action. Analyzing the Schr\"odinger equation, we discuss the mass spectrum and the wave function of the glueball. The lowest glueball state is found to have the mass $M_G \sim 1.6 GeV$ and the size $R_G \sim 0.5 fm$.