Thermal Green Functions in Coordinate Space for Massless Particles of any Spin

The thermal Wightman functions for free, massless particles of spin 0, 1/2, 1, 3/2, and 2 are computed directly in coordinate space by solving the appropriate differential equation and imposing the Kubo-Martin-Schwinger condition. The solutions are valid for real, imaginary, or complex time. The Wightman functions for spin 1 gauge bosons and for spin 2 gravitons are directly related to the fundamental functions for spin 0. The Wightman functions for spin 3/2 gravitinos is directly related to that for spin 1/2 fermions. Calculations for spin 1, 3/2, and 2 are done in covariant gauges. In the deep space-like region the Wightman functions for bosons fall like $T/r$ whereas those for the fermions fall exponentially. In the deep time-like region all the Wightman functions fall exponentially.Comment: 8 pages, RevTex twocolum

Chiral Phase Transitions in QCD at Finite Temperature: Hard-Thermal-Loop Resummed Dyson-Schwinger Equation in the Real Time Formalism

Chiral phase transition in thermal QCD is studied by using the Dyson-Schwinger (DS) equation in the real time hard thermal loop approximation. Our results on the critical temperature and the critical coupling are significantly different from those in the preceding analyses in the ladder DS equation, showing the importance of properly taking into account the essential thermal effects, namely the Landau damping and the unstable nature of thermal quasiparticles.Comment: 4 pages including 2 figures (ps file), to appear in the proceedings of the 4th International Conference on Physics and Astrophysics of Quark-Gluon Plasma (ICPAQGP-2001), 26-30 November 2001, Jaipur, Indi