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

dc.creatorChang, Ngee Pong
dc.date1994-10-04
dc.date1994-10-13
dc.date.accessioned2026-07-07T09:00:07Z
dc.date.available2026-07-07T09:00:07Z
dc.description< \psibarpsi > 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 < \psibarpsi > 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.
dc.description4 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)
dc.identifierhttps://arxiv.org/abs/hep-ph/9410216
dc.identifierhttp://arxiv.org/abs/hep-ph/9410216
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/147939
dc.subjectHigh Energy Physics - Phenomenology
dc.titleChiral Restoration in the Early Universe: Pion Halo in the Sky
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