Makdisi, Y. | Search NASA

DOE OSTI2021

A fixed-target programme at the LHC: Physics case and projected performances for heavy-ion, hadron, spin and astroparticle studies

Here we review the context, the motivations and the expected performances of a comprehensive and ambitious fixed-target programme using the multi-TeV proton and ion LHC beams. We also provide a detailed account of the different possible technical implementations ranging from an internal wire target to a full dedicated beam line extracted with a bent crystal. The possibilities offered by the use of the ALICE and LHCb detectors in the fixed-target mode are also reviewed.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2020

Systematic error analysis in the absolute hydrogen gas jet polarimeter at RHIC

The Polarized Atomic Hydrogen Gas Jet Target polarimeter (HJET) is operated at the Relativistic Heavy Ion Collider (RHIC) since 2004 to measure the absolute polarization of each colliding proton beam. Polarimeter detectors and data acquisition were upgraded in 2015 to increase the solid angle, energy range, and to improve the energy and time resolution. These upgrades along with an improved beam intensity and polarization allowed us to greatly reduce the statistical and systematic errors for the proton polarization measurements in RHIC Runs 15 (E beam = 100 GeV) and 17 (255 GeV). For a typical 8 hour RHIC store, the measured proton beam average polarization was about P beam ~ 55 ± 2.0 stat ± 0.3 syst %. The elastic pp analyzing power, AN(t)~0.04, was determined with a precision of about |δA N (t)|~0.0002 in the momentum transfer squared range 0.001<-t<0.020 GeV 2 . In this paper we present a detailed systematic error analysis of the polarization measurements at HJET. Perspectives of using the HJET based absolute polarimeters in the future Electron Ion Collider (EIC) will be also discussed.

43 PARTICLE ACCELERATORS↗