2010/11/25 by Abdel Nasser Tawfik, A. Tawfik
Physics and Astronomy · #Antimatter #Antiproton #Asymmetry #Cosmology and Gravitation Theories #Electron #Hadron #Hadronization #High-Energy Particle Collisions Research #Large Hadron Collider #Nuclear physics #Particle physics #Physics #Positron #Proton #Statistical Mechanics and Entropy #hep-ph #nucl-th
paper · pdf · doi:10.1016/j.nuclphysa.2011.04.014
published as Nucl.Phys.A859:63-72,2011 · 5 pages, 1 eps figure, revtex4-style
arxiv created 2010/11/25 · openalex publication_date 2011/05/02 · arxiv updated 2011/07/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Assuming that the final state of hadronization takes place along the freezeout line, which is defined by a constant entropy density, the antiproton-to-proton ratios produced in heavy-ion collisions are studied in framework of the hadron resonance gas (HRG) model. A phase transition from quark--gluon plasma to hadrons, a hadronization, has been conjectured in order to allow modifications in the phase space volume and thus in single--particle distribution function. Implementing both modifications in the grand--canonical partition function and taking into account the experimental acceptance in heavy-ion collisions, the antiproton-to-proton ratios over center-of-mass energies √(s) ranging from AGS to RHIC are very well reproduced by the HRG model. Comparing with the same particle ratios in pp collisions results in a gradually narrowing discrepancy with increasing √(s). At LHC energy, the ALICE antiproton-to-proton ratios in pp collisions turn to be very well described by HRG model as well. It is likely that the ALICE heavy-ion program will produce the same antiproton-to-proton ratios as the pp program. Furthermore, the ratio gets very close to unity indicating that the matter-antimatter asymmetry nearly vanishes. The chemical potential calculated at this energy strengthens the assumption of almost fully matter-antimatter symmetry at LHC energy.