Abstract

Precise and absolute beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin‐dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy of ΔPbeam/Pbeam<5%. The absolute polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left‐right pairs of silicon strip detectors and was installed in the RHIC‐ring in 2004. This system features proton‐proton elastic scattering in the Coulomb nuclear interference (CNI) region. Precise measurements of the analyzing power AN of this process has allowed us to achieve ΔPbeam/Pbeam = 4.2% in 2005 for the first long spin‐physics run. In this report, we describe the entire set up and performance of the system. The procedure of beam polarization measurement and analysis results from 2004–2005 are described. Physics topics of AN in the CNI region (four‐momentum transfer squared 0.001<−t<0.032(GeV/c)2) are also discussed. We point out the current issues and expected optimum accuracy in 2006 and the future.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.