2002/07/31 by Masayasu Harada, Youngman Kim, Mannque Rho +1 · 2 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph #nucl-th
paper · pdf · doi:10.1016/j.nuclphysa.2003.07.014
published as Nucl.Phys. A727 (2003) 437-463 · 32 pages, 2 figures
arxiv created 2003/04/15 · openalex publication_date 2003/09/03 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
The question as to what the relevant effective degrees of freedom at the chiral phase transition are remains largely unanswered and must be addressed in confronting both terrestrial and space laboratory observations purporting to probe matter under extreme conditions. We address this question in terms of the vector susceptibility χV (VSUS in short) and the axial-vector susceptibility χA (ASUS in short) at the temperature-induced chiral transition. We consider two possible, albeit simplified, cases that are contrasting, one that is given by the standard chiral theory where only the pions figure in the vicinity of the transition and the other that is described by hidden local symmetry (HLS) theory with the Harada-Yamawaki vector manifestation (VM) where nearly massless vector mesons also enter. We find that while in the standard chiral theory, the pion velocity vπproportional to the ratio of the space component fπs of the pion decay constant over the time component fπt tends to zero near chiral restoration with fπt≠ 0, in the presence of the vector mesons with vanishing mass, the result is drastically different: HLS with VM \it predicts that χV automatically equals χA in consistency with chiral invariance and that vπ∼ 1 with fπt≈ fπs→ 0 as T→ Tc. These results are obtained in the leading order in power counting but we expect their qualitative features to remain valid more generally in the chiral limit thanks to the VM point.