The Gluon Spin Structure Function From SLAC E161

摘要

We will determine the gluon spin density Δg(x) in the nucleon by measuring the asymmetry for polarized photo-production of charmed quarks from polarized targets in End Station A at SLAC. The quasi-mono-chromatic circularly polarized photon beam will be produced from an oriented diamond crystal. The target will be longitudinally polarized LiD at a temperature of 0.3 K, centered in a 6.5 T magnetic field to obtain high polarization. Photo-production of open charm will be tagged by decays of D mesons into high transverse momentum muons. The asymmetry for single muons will be measured as a function of muon momentum, muon transverse momentum, and photon beam energies with sufficient precision to discriminate among models of Δg(x) that differ from each other by as little as 10% in the range 0.1 < x < 0.2.