ar X iv : n uc l - ex / 0 00 90 05 v 1 6 S ep 2 00 0 Overview of the Status and Strangeness Capabilities of STAR

STAR is a large acceptance spectrometer capable of precision measurements of a wide variety of strange particles. We discuss the STAR detector, its configuration during the first two years of RHIC operation, and its initial performance for Au+Au collisions. The expected performance for strangeness physics and initial data on strange particle reconstruction in Au+Au collisions are presented. The STAR detector at RHIC [1] is a large acceptance spectrometer with a very broad physics program, including precision measurements of a wide variety of strange particles. The STAR experimental configuration during the early years of RHIC operation is shown in Figure 1. For the first year of RHIC running, the active detectors are the Time Projection Chamber (TPC), the Zero Degree Calorimeters (ZDC) [2], the Central Trigger Barrel (CTB), and the Ring Imaging Cerenkov Counter (RICH). The solenoidal magnet has a maximum field strength of 0.5 Tesla but for the first year is run at 0.25 Tesla. For operation in the second year, STAR will install the Silicon Vertex Tracker (SVT), two forward TPCs (FTPC), a time-of-flight (TOF) patch, and 26 modules of the Barrel Electromagnetic Calorimeter (EMC), comprising 22% of the full barrel EMC which will be completed by 2003. Details on the acceptance of the various detector components relevant for strange particle reconstruction are given in the following section. RHIC began operations for physics in the summer of 2000. Together with the other RHIC experiments, STAR observed collisions immediately. The quality of track reconstruction in the TPC is high and efforts to understand and quantify the tracking efficiency are underway. The performance of the STAR TPC is illustrated in Figure 2. The left panel shows the specific ionization (truncated mean dE/dx) in the TPC for Au+Au collisions at √ s N N = 130 GeV, as a function of track momentum. The curves are the Bethe-Bloch parameterization of dE/dx. The bands for pions, kaons, protons, deuterons and electrons are visible. The relative dE/dx resolution is approaching the design goal of 8%. The left panel shows the momentum resolution of the TPC as a function of momentum for charged tracks from cosmic rays that have been independently reconstructed in the upper and lower halves of the TPC in a 0.5 Tesla magnetic field. The solid curve labelled " CDR " is the design goal, with the difference from measurement due in large part to known instrumental effects that have since been …