The STAR experiment at RHIC is equipped with insertion devices (Roman Pots) that allow the detectors to be moved close to the beam, in order to measure protons at small scattering angles. This setup, together with the unique capability of RHIC to collide spin-polarized proton beams, allows STAR to study both unpolarized and spin-dependent proton-proton (pp) elastic scattering process. With silicon strip detectors installed in Roman Pots, pp elastic scattering is accessible in the Coulomb Nuclear Interference (CNI) region, where a measurable single spin asymmetry arises. By using a dedicated run with special beam optics during the RHIC 2009 data taking period, the collaboration was able to collect more than 30 M elastic triggers with transversely polarized proton beams at √s = 200 GeV and in the four-momentum transfer squared (t) range of 0.005 GeV2/c2 ≤ -t ≤ 0.035 GeV 2/c2. In here we describe the experimental setup and performance during the last data taking period, with a specific focus on alignment and efficiency of the silicon detectors.
ASJC Scopus subject areas
- Physics and Astronomy(all)