New nonperturbative approach to the Debye mass in hot QCD

The Debye mass m_D is computed nonperturbatively in the deconfined phase of QCD, where chromomagnetic confinement is known to be present. The latter defines m_D to be m_D=c_D\sqrt{\sigma_s}, where c_D \cong 2.06 and \sigma_s=\sigma_s(T) is the spatial string tension. The resulting magnitude of m_D(T) and temperature dependence are in good agreement with lattice calculations. Background perturbation theory expansion for m_D(T) is discussed in comparison to standard perturbative results and recent gauge-invariant definitions.