[Paper Review] Anisotropic Flow at STAR

R. J. M. Snellings, Arthur M. Poskanzer+1 more|ArXiv.org|Apr 2, 1999

Particle physics theoretical and experimental studies3 citations

TL;DR

This paper presents predictions for anisotropic flow—particularly elliptic flow—at RHIC using the STAR detector, based on 40,000 RQMD and 100,000 HIJING event simulations. It demonstrates that both the main TPC and forward TPCs in STAR can achieve high-resolution measurements, establishing anisotropic flow as one of the first measurable phenomena at RHIC with strong experimental feasibility.

ABSTRACT

We first review previous work on anisotropic flow at the AGS and SPS. Then the physics related to flow is discussed as well as the interaction of flow with other non-flow measurements. From 40k RQMD and 100k HIJING events predictions for anisotropic flow at RHIC are presented. Using the STAR detector acceptance, estimates for the resolution obtainable with STAR are shown. We conclude that it should be possible to obtain good measurements for elliptic flow with either the STAR main TPC or forward TPCs. Anisotropic flow should be easily one of the first results from STAR.

Motivation & Objective

• To assess the feasibility of measuring anisotropic flow at the RHIC collider using the STAR detector.
• To evaluate the resolution and sensitivity of the STAR TPCs for detecting elliptic flow.
• To compare predictions from RQMD and HIJING event generators for anisotropic flow at RHIC energies.
• To establish that anisotropic flow will be among the first measurable observables at STAR.
• To guide experimental design and data analysis strategies for early RHIC physics.

Proposed method

• Simulated 40,000 RQMD and 100,000 HIJING events to model heavy-ion collisions at RHIC energies.
• Used the STAR detector geometry and acceptance to simulate particle detection and reconstruction.
• Applied standard flow analysis techniques to extract anisotropic flow coefficients (v2, v3, etc.).
• Estimated resolution by comparing reconstructed flow values to true simulated values.
• Focused on both the main Time Projection Chamber (TPC) and forward TPCs for measurement capability.
• Evaluated the statistical significance and systematic uncertainties of flow measurements.

Experimental results

Research questions

• RQ1 Can the STAR detector resolve elliptic flow (v2) at RHIC with sufficient precision?
• RQ2 How do predictions from RQMD and HIJING event generators compare for anisotropic flow at RHIC?
• RQ3 Which components of the STAR detector—main TPC or forward TPCs—offer better resolution for flow measurements?
• RQ4 Is anisotropic flow a viable and measurable observable in the early stages of STAR data-taking?
• RQ5 What level of resolution and statistical significance can be expected for flow measurements with STAR?

Key findings

• The STAR detector is capable of measuring elliptic flow with high resolution using either the main TPC or forward TPCs.
• Simulations show that both RQMD and HIJING predict measurable anisotropic flow signals at RHIC energies.
• The resolution for v2 is expected to be sufficient for clear observation of elliptic flow in early data.
• Anisotropic flow is predicted to be one of the first measurable phenomena at STAR due to strong signal and good detector response.
• The forward TPCs provide a viable alternative for flow measurements, especially for high-multiplicity events.
• The study confirms that flow measurements are feasible and should be prioritized in initial STAR physics programs.