Imaging of granular sources in high energy heavy ion collisions

Abstract

We investigate the source imaging for a granular pion-emitting source model in high energy heavy ion collisions. The two-pion source functions of the granular sources exhibit a two-tiered structure. Using a parametrized formula of granular two-pion source function, we examine the two-tiered structure of the source functions for the imaging data of Au+Au collisions at Alternating Gradient Synchrotron (AGS) and Relativistic Heavy Ion Collider (RHIC). We find that the imaging technique introduced by Brown and Danielewicz is suitable for probing the granular structure of the sources. Our data-fitting results indicate that there is not visible granularity for the sources at AGS energies. However, the data for the RHIC collisions with the selections of $40<\mathrm{centrality}<90$ and $0.20<k_{\mathrm{T}}<0.36$ GeV/c are better described by the model with granular emission than that of one Gaussian. The model with granular source has more parameters than the simple Gaussian, hence can describe more complicated shapes.

14 pages, 6 figures

References in corpus (6)

• Importance of Granular Structure in the Initial Conditions for the Elliptic Flow
• Evidence for a long-range component in the pion emission source in Au+Au collisions at sqrt(s_NN) = 200 GeV
• Analysis of pion elliptic flows and HBT interferometry in a granular quark-gluon plasma droplet model
• Analyzing Correlation Functions with Tesseral and Cartesian Spherical Harmonics
• Exploring Lifetime Effects in Femtoscopy
• Single-Event Handbury-Brown-Twiss Interferometry

Cited by in corpus (2)

• Characteristic quantities of pion-emitting sources extracted by model-independent analysis in relativistic heavy ion collisions
• The Kolmogorov-Smirnov test and its use for the identification of fireball fragmentation