May 13 – 19, 2018
Venice, Italy
Europe/Zurich timezone
The organisers warmly thank all participants for such a lively QM2018! See you in China in 2019!

Angular Correlations Study of Identified Hadrons in the STAR Beam Energy Scan Program

May 15, 2018, 5:00 PM
2h 40m
First floor and third floor (Palazzo del Casinò)

First floor and third floor

Palazzo del Casinò

Poster Correlations and fluctuations Poster Session


Andrzej Lipiec (Warsaw University of Technology)


The angular correlation function (CF) refers to the correlation of particles in the relative pseudorapidity ($\Delta\eta$) and relative azimuthal angle ($\Delta\phi$). CF is influenced by various physical phenomena such as conservation laws, collective particle flow, resonance decays, final state interactions, or particle production mechanism - e.g., correlation of particles within the single jet. By analysis of long-range correlations (of pairs with $\Delta\eta \geq$1.0) it is possible to access the early stage of the system created during heavy-ion collision and its longitudinal and azimuthal dynamics.

The STAR Beam Energy Scan data allows one to perform a detailed CF analysis to investigate the phase diagram of strongly interacting matter. Recently [1] STAR reported an angular correlation measurements of $\pi$-$\pi$, K-K, and p-p pairs with $\Delta \eta \leq$1 in 0-5% central Au+Au collision at $\sqrt{s_{NN}}$ = 7.7-200 GeV. These results show a significant difference between CF of given particle species combinations.

In this poster, we extend this results to $\Delta \eta \leq\;$2, which allows for analysis of long-range correlations of $\pi$-$\pi$, K-K, and p-p pairs. We describe the data by fitting a multi-component function. Such an approach allows for disentanglement of various correlation sources. The study is conducted in nine centrality classes (70-80%, 60-70%, 50-60%, 40-50%, 30-40%, 20-30%, 10-20%, 5-10% and 0-5%) of Au+Au collisions at $\sqrt{s_{NN}}$ between 7.7 and 200 GeV. The collision energy and centrality dependence of the best fit-to-data function parameters, describing short- and long-range correlations, will be presented.

[1] S. Jowzaee (for the STAR Collaboration), Nucl. Phys. A967, 792 (2017).

Centralised submission by Collaboration Presenter name already specified
Collaboration STAR
Content type Experiment

Primary author

Zhenyu Ye (University of Illinois at Chicago)

Presentation materials