2014/03/28 by Taesoo Song, Song, Taesoo, Che Ming Ko +1
Physics and Astronomy · #FOS: Physical sciences #High-Energy Particle Collisions Research #Nuclear Experiment (nucl-ex) #Nuclear Theory (nucl-th) #Nuclear physics research studies #Quantum Chromodynamics and Particle Interactions #nucl-ex #nucl-th
paper · pdf · doi:10.48550/arxiv.1403.7363
9 pages, 6 figures
arxiv created 2014/03/28 · openalex publication_date 2014/03/28 · arxiv updated 2014/03/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Using the relativistic Vlasov-Uehling-Uhlenbeck (RVUU) equation based on mean fields from the nonlinear relativistic models, we study the effect of medium modification of pion production threshold on the total pion yield and the π-/π+ ratio in Au+Au collisions. We find that the in-medium threshold effect enhances both the total pion yield and the π-/π+ ratio, compared to those without this effect. Furthermore, including the medium modification of the pion production threshold in asymmetric nuclear matter leads to a larger π-/π+ ratio for the NLρδ model with a stiffer symmetry energy than the NLρ model with a softer symmetry energy, opposite to that found without the in-medium threshold effect. Experimental data from the FOPI Collaboration are reproduced after including a density-dependent cross section for Δ baryon production from nucleon-nucleon collisions, which suppresses the total pion yield but hardly changes the π-/π+ ratio. The large errors in the experimentally measured π-/π+ ratio prevent, however, the distinction between the predictions from the NLρ and NLρδ models.