2009/12/31 by T. Antičić, The NA49 Collaboration, B. Baatar +83 · 1 citation
Mathematics · Physics and Astronomy · #Critical point (mathematics) #Geometry #Hadron #High-Energy Particle Collisions Research #Invariant mass #Large Hadron Collider #Mathematics #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Pion #Power law #Proton #Proton Synchrotron #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quantum mechanics #Sigma #Statistics #Super Proton Synchrotron #Synchrotron #hep-ex #hep-ph #nucl-ex
paper · pdf · doi:10.1103/physrevc.81.064907
published as Phys.Rev.C81:064907,2010 · 31 pages, 11 figures
arxiv created 2010/05/19 · openalex publication_date 2010/06/01 · arxiv updated 2014/11/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Pion production in nuclear collisions at the Super Proton Synchrotron (SPS) is investigated with the aim to search, in a restricted domain of the phase diagram, for power laws in the behavior of correlations that are compatible with critical QCD. We analyzed interactions of nuclei of different sizes (p+p, C+C, Si+Si, Pb+Pb) at 158A GeV adopting, as appropriate observables, scaled factorial moments in a search for intermittent fluctuations in transverse dimensions. The analysis is performed for π+π- pairs with an invariant mass very close to the two-pion threshold. In this sector one may capture critical fluctuations of the sigma component in a hadronic medium, even if the σ meson has no well-defined vacuum state. It turns out that for the Pb+Pb system the proposed analysis technique cannot be applied without entering the invariant mass region with strong Coulomb correlations. As a result the treatment becomes inconclusive in this case. Our results for the other systems indicate the presence of power-law fluctuations in the freeze-out state of Si+Si approaching in size the prediction of critical QCD