DUAL HIGGS MECHANISM FOR QUARKS IN HADRONS

We study nonperturbative features of QCD using the dual Ginzburg-Landa u (DGL) theory, where the color confinement is realized through the du al Higgs mechanism brought by QCD-monopole condensation. The linear co nfinement potential appears in the QCD-monopole condensed vacuum. Pie study the infrared screening effect to the confinement potential by th e light-quark pair creation, and derive a compact formula for the scre ened quark potential. We study the dynamical chiral-symmetry breaking (DchiSB) in the DGL theory by solving the Schwinger-Dyson equation. QC D-monopole condensation plays an essential role to DchiSB. The QCD pha se transition at finite temperature is studied using the effective pot ential formalism in the DGL theory. We find the reduction of QCD-monop ole condensation and the string tension at high temperatures. The surf ace tension is calculated using the effective potential at the critica l temperature T-c. The DGL theory predicts a large mass reduction of g lueballs near T-c. We apply the DGL theory to the quark-gluon-plasms ( QGP) physics in the ultrarelativistic heavy-ion collisions. We propose a new scenario of the QGP formation via the annihilation of color-ele ctric flux tubes based on the attractive force between them.