In the lattice gauge-scalar model with a single scalar field in the fundamental representation of the gauge group $SU(2)$, we have quite recently found that there exists a gauge-independent transition line separating the Confinement and Higgs phases without contradicting the well-known sterwalder-Seiler-Fradkin-Shenker analyticity theorem between the two phases by performing numerical simulations without any gauge fixing. This was achieved by examining the correlation between the original fundamental scalar field and the so-called color-direction field constructed from the gauge field through the gauge-covariant decomposition due originally to Cho-Duan-Ge-Shabanov and Faddeev-Niemi.
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In this presentation, we give further numerical evidence for the gauge-independent separation between the Confinement and Higgs phases in the above model to establish their physical origin. For this purpose, we investigate the separation line precisely.
We also investigate the contributions of magnetic monopoles to examine their role in confinement %and mass generation (mass gap) from the viewpoint of the dual uperconductor picture.
