2002/06/07 by Agnes Mocsy, Ágnes Mócsy
Physics and Astronomy · #Condensed matter physics #Dispersion relation #Dissipation #Dissipative system #High-Energy Particle Collisions Research #Meson #Particle physics #Particle physics theoretical and experimental studies #Phase transition #Physics #Pion #Quantum Chromodynamics and Particle Interactions #Quantum electrodynamics #Quantum mechanics #Relaxation (psychology) #Sigma #Sigma model #Thermal #Thermal equilibrium #Thermal fluctuations #Thermal quantum field theory #Thermodynamics #Work (physics) #hep-ph
paper · pdf · doi:10.1103/physrevd.66.056010
published as Phys.Rev. D66 (2002) 056010 · 32 pages, 9 ps figures
arxiv created 2002/06/07 · openalex publication_date 2002/09/26 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A simple and consistent real time analysis of the long-wavelength chiral condensate fields in the background of hard thermal modes is presented in the framework of the linear sigma model. Effective evolution equations are derived for the inhomogeneous condensate fields coupled to a heat bath. The multiple effects of the thermal background on the disoriented chiral condensate are studied using linear response theory. I determine the temperature dependence of the equilibrium condensate, and examine the modification of the sigma and pion dispersion relations as these mesons traverse a hot medium. I calculate the widths by determining the dissipative coefficients at nonzero temperature at one- and two-loop order with resummed meson masses. My results show that not only decay processes, but elastic scattering processes are significant at high temperatures, yielding to short relaxation times in the phase transition region. The relaxation times obtained are shorter than in previous estimates, making the observation of disoriented chiral condensate signals questionable. Throughout this work Goldstone's theorem is satisfied when chiral symmetry is spontaneously broken.