Chiral Restoration in the Early Universe: Pion Halo in the Sky

vanishing above $T_c$ indicates chiral symmetry restoration at high $T$. But is it the old $T=0$ chiral symmetry that is `restored'? In this talk, I report on the spacetime quantization of the BPFTW effective action for quarks in a hot environ. The fermion propagator is known to give a pseudo-Lorentz invariant particle pole as well as new spacelike cuts. Our quantization shows that the spacelike cuts directly lead to a thermal vacuum that is a generalized NJL state, with a curious $90^{o}$ phase. This $90^{o}$ is responsible for vanishing at high $T$. The thermal vacuum is invariant under a new chiral charge, but continues to break the old zero temperature chirality. Our quantization suggests a new class of order parameters that probe the physics of these spacelike cuts. In usual scenario, the pion dissociates in the early alphabet soup. With this new understanding of the thermal vacuum, the pion remains a Nambu-Goldstone particle at high $T$, and will not dissociate. It propagates at the speed of light but with a halo.Comment: 4 pages, LaTeX, CCNY-HEP-94-9 To appear in Proceedings of "Trends in Astroparticle Physics Workshop", Stockholm, Sweden, 22-25 September, 1994, Nuclear Physics B, Proceedings Supplement, edited by L. Bergstrom, P. Carlson, P.O. Hulth, and H. Snellman. (Only revision is in the header citation

Spacetime Quantization of BPFTW Action: Spacelike Plasmon Cut \& New Phase of the Thermal Vacuum

In this paper, we perform the quantization of the nonlocal BPFTW effective action in coordinate space. The action is made local by using a conjugate set of auxiliary fields. The action summarizes the properties of quark propagation through a hot environ. The fermion propagator shows a pseudo-Lorentz invariant particle pole as well as a pair of conjugate spacelike plasmon cut. We relate the cuts to the homogeneous solutions of the local equations of motion for auxiliary fields. Our quantization shows how the spacelike cut produces a $90^{o}$ phase factor in the thermal vacuum at high $T$. This phase factor is responsible for the vanishing of \psibarpsi at high $T$.Comment: 9 pages, LaTeX, CCNY-HEP-94-