The STAR event plane detector

Abstract

The Event Plane Detector (EPD) is an upgrade detector to the STAR experiment at RHIC, designed to measure the pattern of forward-going charged particles emitted in a high-energy collision between heavy nuclei. It consists of two highly-segmented discs of 1.2-cm-thick scintillator embedded with wavelength-shifting fiber, coupled to silicon photomultipliers and custom electronics. We describe the general design of the device, its construction, and performance on the bench and in the experiment.

Investigation of the Elliptic Flow Fluctuations of the Identified Particles Using the a Multi-Phase Transport Model

“…For RHIC highest energy and using the STAR detector, we propose a similar investigation to be performed using the first-order spectator event plane from spectator neutrons, measured by the zero-degree calorimeters (ZDC) [54] and the second-order event plane using the new installed Event-Plane-Detector (EPD) [55]. Consequently, we think that conducting a similar experimental study will reveal important information about the elliptic flow fluctuations and will shed light on the ICCING scenario suggested in Reference [50].…”

Testing the impact of electromagnetic fields on the directed flow of constituent quarks in heavy-ion collisions

“…Here we use the factor (C Res EP ) to account for the high event-plane resolution provided by the STAR Event Plane Detector (EPD) [36] since 2018, relative to the previously used Beam-Beam Counter (BBC) [37]. For Au+Au collisions at √ s N N = 27 GeV and 10-40% centrality, we obtain k = 3.48 with N BES−I evt = 70M [24], N BES−II evt = 400M [35] and C Res EP = 1.45 [36] (for midcentral collisions). Then the uncertainty projections for d∆v 1 /dy in BES-II, estimated by scaling the corresponding numbers for BES-I with the obtained k factor, are shown by solid green bands in Fig.…”

Azimuthal anisotropy measurement of $ϕ$ mesons in Au+Au collisions at $\sqrt{s_{NN}}$ = 27 and 54.4 GeV at STAR

“…The main STAR detectors that we have used in our analysis is the Time Projection Chamber (TPC), Time Of Flight (TOF) detector and Event Plane Detectors (EPDs) [5,6]. The TPC is a cylindrical detector having a length of 4.2m and a radius of 4m which surrounds the beam pipe.…”