A Planned Jefferson Lab Experiment on Spin-Flavor Decomposition

Abstract

Experiment E04-113 at Jefferson Lab Hall C plans to measure the beam-target double-spin asymmetries in semi-inclusive deep-inelastic $\vec{p}(e,e^{\prime }h)X$ and $\vec{d}(e,e^{\prime }h)X$ reactions ($h={\pi }^{+},{\pi }^{-},K^{+}$ or$K^{-}$) with a 6 GeV polarized electron beam and longitudinally polarized NH${}_3$ and LiD targets. The high statistic data will allow a spin-flavor decomposition in the region of $x=0.12\sim 0.41$ at $Q^2=1.21\sim 3.14$ GeV${}^2$. Especially, leading-order and next-to-leading order spin-flavor decomposition of $\Delta u_v$, $\Delta d_v$ and $\Delta \bar{u}-\Delta \bar{d}$ will be extracted based on the measurement of the combined asymmetries $A_{1N}^{{\pi }^{+}-{\pi }^{-}}$. The possible flavor asymmetry of the polarized sea will be addressed in this experiment.

Comments: 4 pages, 2 figures, contribution paper to SPIN2004 conference