1998/03/31 by Guangjun Mao, L. Neise, H. Stöcker +2 · 2 citations
Physics and Astronomy · #Dispersion relation #Hadron #High-Energy Particle Collisions Research #Mathematical physics #Momentum (technical analysis) #Nuclear matter #Nuclear physics #Nuclear physics research studies #Nucleon #Particle physics #Physics #Pion #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #nucl-th
paper · pdf · doi:10.1103/physrevc.59.1674
published as Phys. Rev. C59 (1999) 1674-1699. · 66 pages, Latex, 12 PostScript figures included; replaced by the revised version, to appear in Phys. Rev. C
arxiv created 1998/12/09 · openalex publication_date 1999/03/01 · openalex created_date 2016/06/24 · arxiv updated 2016/08/14 · openalex updated_date 2026/08/05
We derive the relativistic quantum transport equation for the pion distribution function based on an effective Lagrangian of the QHD-II model. The closed-time-path Green's function technique and the semiclassical, quasiparticle, and Born approximations are employed in the derivation. Both the mean field and collision term are derived from the same Lagrangian and presented analytically. The dynamical equation for the pions is consistent with that for the nucleons and \ensuremathΔ's which we developed before. Thus, we obtain a relativistic transport model which describes the hadronic matter with N, \ensuremathΔ, and \ensuremathπ degrees of freedom simultaneously. Within this approach, we investigate the medium effects on the pion dispersion relation as well as the pion absorption and pion production channels in cold nuclear matter. In contrast to the results of the nonrelativistic model, the pion dispersion relation becomes harder at low momenta and softer at high momenta as compared to the free one, which is mainly caused by the relativistic kinetics. The theoretically predicted free \ensuremathπ\stackrel\ensuremath→N\ensuremathΔ cross section is in agreement with the experimental data. Medium effects on the \ensuremathπ\stackrel\ensuremath→N\ensuremathΔ cross section and momentum-dependent \ensuremathΔ-decay width are shown to be substantial.