Centrality Dependent Lévy-Stable Two-Pion Bose-Einstein Correlations in ( {sqrt{s_{NN}}} ) = 200 GeV Au+Au Collisions at the PHENIX Experiment

摘要

Investigation of femtoscopic correlation functions in relativistic heavy ion reactions is an important tool to access the space-time structure of particle production in the strongly interacting Quark Gluon Plasma (sQGP). The shape of the source, and thus the shape of the correlation functions, is often assumed to be Gaussian, but experimental results found evidence for heavy tails in the source distribution of pions. Recent analysis revealed that the statistically correct assumption could be the so-called Lévy distribution. The detailed investigation of correlation functions in various systems may shed light on the location of the critical endpoint on QCD (Quantum Chromodynamics) phase diagram. It could also reveal if there is partially coherent pion production or could indicate the possible in-medium mass modification of the η ′ meson due to the (partial) restoration of the U A ( 1 ) axial symmetry. These phenomena could depend on the system size and on the collision energy. A detailed centrality-dependent analysis could explore the multiplicity dependencies of the Lévy parameters, and thus the critical and thermodynamical properties of the sQGP, and could give information about the above mentioned processes. In this paper, we present the status of the centrality dependent measurements of two-pion Lévy Bose-Einstein correlation functions s NN = 200 GeV Au+Au collisions at PHENIX.