Evidence for a single-spin azimuthal asymmetry in semi-inclusive pion electroproduction
Evidence for a single-spin azimuthal asymmetry in semi-inclusive pion electroproduction
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DOI：
10.1103/physrevlett.84.4047
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发表时间：
1999-10
影响因子：
8.6
通讯作者：
A. Airapetian;E. al.
中科院分区：
文献类型：
--
作者：
A. Airapetian;E. al.
首次测量了深度非弹性散射中半包容介子产生的单自旋不对称性。在纵向极化氢靶上产生π(+)电产生时，π介子相对于轻子散射面在方位角直线上的分布具有明显的靶自旋不对称性。截面单直φ矩对应的分析功率为0.022+/-0.005+/-0.003。这一结果可以解释为涉及手性奇自旋分布函数的横截面项与手性奇碎片化函数的作用，该函数对碎片化夸克的横向极化敏感。
Single-spin asymmetries for semi-inclusive pion production in deep-inelastic scattering have been measured for the first time. A significant target-spin asymmetry of the distribution in the azimuthal angle straight phi of the pion relative to the lepton scattering plane was formed for pi(+) electroproduction on a longitudinally polarized hydrogen target. The corresponding analyzing power in the sinstraight phi moment of the cross section is 0.022+/-0.005+/-0.003. This result can be interpreted as the effect of terms in the cross section involving chiral-odd spin distribution functions in combination with a chiral-odd fragmentation function that is sensitive to the transverse polarization of the fragmenting quark.