Casimir scaling in a dual superconducting scenario of confinement
Abstract
The string tensions of flux tubes associated with static charges in various SU(3) representations are studied within the dual Ginzburg-Landau (DGL) theory. The ratios of the string tensions between higher and fundamental representations, d_{D} \equiv \sigma_{D}/\sigma_{F}, are found to depend only on the Ginzburg-Landau (GL) parameter, \kappa = m_{\chi}/m_{B}, the mass ratio between monopoles m_\chi and dual gauge bosons m_B. In the case of the Bogomol'nyi limit (\kappa=1), analytical values of d_{D} are easily obtained by adopting the manifestly Weyl invariant formulation of the DGL theory, which are provided simply by the number of color-electric Dirac strings inside the flux tube. A numerical investigation of the ratio for various GL-parameter cases is also performed, which suggests that the Casimir scaling is obtained in the type-II parameter range within the interval \kappa=5 \sim 9 for various ratios d_D.