Role of dual Higgs mechanism in chiral phase transition at finite temperature

The chiral phase transition at finite temperature is studied by using the Schwinger-Dyson equation in the dual Ginzburg-Landau theory, in which the dual Higgs mechanism plays an essential role on both the color confinement and the spontaneous chiral-symmetry breaking. At zero temperature, the quark condensate is strongly correlated with the string tension, which is generated by QCD-monopole condensation, as \langle {\bar q}q \rangle^{1/3} \stackrel{\propto}{\scriptstyle \sim} \sqrt{\sigma}. In order to solve the finite-temperature Schwinger-Dyson equation numerically, we provide a new ansatz for the quark self-energy in the imaginary-time formalism. The recovery of the chiral symmetry is found at high temperature; T_{_{C}}\sim 100{\rm MeV} with realistic parameters. We find also a strong correlation between the critical temperature T_{_{C}} of the chiral symmetry restoration and the strength of the string tension