1994/10/04 by Ngee Pong Chang, Chang, Ngee Pong
Physics and Astronomy · #Cosmology and Gravitation Theories #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Particle physics theoretical and experimental studies #Scientific Research and Discoveries
paper · pdf · doi:10.48550/arxiv.hep-ph/9410216
openalex publication_date 1994/10/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
< \psibarpsi > vanishing above Tc 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 90o phase. This 90o 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.