Geometry of particle emission in UrQMD Ar+Sc collisions at SPS energies

Abstract

Over the past few decades, progress in femtoscopy has been driven by the interplay between experimental measurements and theoretical calculations. Measurements provide data to support the theory, while theoretical predictions guide new measurements. In the recent decade, several experiments have confirmed that the two-particle pion-emitting source is well described by Lévy alpha-stable distributions. To enable theoretical interpretation, phenomenological simulations have been done at RHIC and LHC energies, in large systems such as Au+Au or Pb+Pb, using various available heavy-ion collision models. However, such simulations have not been done in intermediate systems. In this paper, we investigate three-dimensional two-pion pair source distributions from ${}^{40}$Ar+${}^{45}$Sc central collisions at SPS energies, generated with the Ultra-Relativistic Quantum Molecular Dynamics Monte-Carlo event generator. Supplemented by a validation of the simulated hadronic spectra, we find that the pair source can be described with Lévy-stable distributions. We subsequently interpret the physical meaning of the extracted Lévy parameters corresponding to the spatial scale, shape, and strength of the source. Our results form a baseline for future experimental measurements in intermediate systems.

arXiv comment12 pages, 8 figures, accepted at Physics Letters B

References in corpus (25)

• Microscopic Models for Ultrarelativistic Heavy Ion Collisions
• Relativistic Hadron-Hadron Collisions in the Ultra-Relativistic Quantum Molecular Dynamics Model (UrQMD)
• Femtoscopy in Relativistic Heavy Ion Collisions: Two Decades of Progress
• NA61/SHINE facility at the CERN SPS: beams and detector system
• Bose-Einstein Correlations for Three-Dimensionally Expanding, Cylindrically Symmetric, Finite Systems
• Bose-Einstein Correlations of Charged Pion Pairs in Au+Au Collisions at sqrt(s_NN)=200_ GeV
• A new cross term in the two-particle Hanbury-Brown-Twiss correlation function
• Imaging of Sources in Heavy-Ion Reactions
• Bose-Einstein correlations for Levy stable source distributions
• Bose-Einstein Correlations for Systems with Large Halo
• Lévy-stable two-pion Bose-Einstein correlations in $\sqrt{s_{{}_{NN}}}=200$ GeV Au$+$Au collisions
• Evidence for a long-range component in the pion emission source in Au+Au collisions at sqrt(s_NN) = 200 GeV
• Quantum Statistical Correlations for Slowly Expanding Systems
• Anomalous diffusion of pions at RHIC
• Event-by-event investigation of the two-particle source function in heavy-ion collisions with EPOS
• Two-pion femtoscopic correlations in Be+Be collisions at $\sqrt{s_{\text{NN}}}=16.84$ GeV measured by the NA61/SHINE at CERN
• Event-by-event investigation of the two-particle source function in $\sqrt{s_{{}_{\text{NN}}}}=2.76$ TeV PbPb collisions with EPOS
• Femtoscopy with Lévy sources from SPS through RHIC to LHC
• Pion interferometry with Lévy-stable sources in $\sqrt{s_{NN}}$ = 200 GeV Au+Au collisions at STAR
• Two-particle Bose-Einstein correlations and their Lévy parameters in PbPb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV
• Lévy walk of pions in heavy-ion collisions
• Centrality dependence of Lévy-stable two-pion Bose-Einstein correlations in $\sqrt{s_{{}_{NN}}}=200$ GeV Au$+$Au collisions
• Femtoscopic signatures of unique nuclear structures in relativistic collisions
• Excitation function of femtoscopic Lévy source parameters of pion pairs in EPOS4
• Three-dimensional sizes and shapes of pion emission in heavy-ion collisions